Grade 8 / Relative numbers: operations 78 exercises corrected

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ChingQuizz : 15 exercises available for Quizz assessment : 1. Reminders: additions E.8664 Rule: The sum of two relative numbers from same sign : has the sign commum to these two relative numbers, whose distance to zero is the sum of their two dis-tances to zero. Examples: (+3)+(+5)=+8 ; ( − 1)+( − 4)= − 5 of opposite signs : has the sign of the number with the greatest distance to zero, whose distance to zero is the difference of the greatest distance to zero by the smallest. Examples: (+2)+( − 7)= − 5 ; ( − 3)+(+5)=+2 Perform the calculations below : a ( − 5) + ( − 3) b (+5) + ( − 3) c (+1) + (+1) d ( − 5) + (+2) e (+3) + ( − 7) f ( − 3) + ( − 3) E.6088 Using mental arithmetic, give the results of the following operations : a (+0.6) + (+1.5) b (+0.8) + ( − 1.5) c ( − 5.1) + ( − 0.7) d ( − 3.2) + ( − 0.5) e (+1.4) + ( − 7) f (+2.2) + (+4.9) 2. Reminders: sum of several terms E.8670 Method : to perform the sum of several relative numbers, we calculate the sum of the positive numbers, calculate the sum of the negative numbers, then add these two sums. Example: Perform the following calculations : a (+3) + ( − 5) + (+1) + ( − 1) b ( − 2) + ( − 4) + (+6) + ( − 1) + (+7) c (+7) + ( − 2) + ( − 4) + (+3) d ( − 2) + (+1) + (+4) + ( − 3) E.8679 Perform the following calculations : a ( − 0.5) + (+2.7) + (+1.5) + ( − 1.7) b ( − 4.1) + (+1.6) + ( − 3.7) + (+0.4) c ( − 3.3) + ( − 1.2) + (+4.5) + ( − 1.2) d (+2.5) + (+1.7) + ( − 7.1) + (+2.4) 3. Reminders: addition and subtraction E.8687 Perform the following calculations : a (+2) + ( − 5) b ( − 3) − ( − 4) c ( − 5) − (+2) d (+2) − ( − 7) e ( − 6) + ( − 2) f (+7) − (+2) E.4342 Rule for subtracting relative numbers: To subtract two relative numbers, add the first number to the opposite of the second number Examples: (+3) − (+5) = (+3) + ( − 5) = − 2 ( − 3) − (+5) = ( − 3) + ( − 5) = ( − 8) Perform the following calculations : a (+5) − (+3) b ( − 3) − ( − 3) c ( − 7) − (+13) https://chingmath.fr quizzChap/1025 chapExoCorrec/8664 sacados/8664 chapExoCorrec/6088 sacados/6088 chapExoCorrec/8670 sacados/8670 A(−(−(−(− chapExoCorrec/8679 sacados/8679 chapExoCorrec/8687 sacados/8687 chapExoCorrec/4342 sacados/4342
E.1711 Perform the following calculations : a ( − 3) + (+7) + (+3) b ( − 7) + ( − 2) + (+4) + ( − 1) c (+7) − ( − 2) + (+4) d (+5) + ( − 4) − (+7) Indication : calculations will be carried out with wording similar to the example opposite : E.8665 Perform the calculations below : a ( − 1.5) − (+2.7) b ( − 0.8) − ( − 1.2) c (+0.8) − ( − 2.2) d (+1.7) − (+2.6) E.8686 Perform the calculations below : a (+2) + ( − 4) − (+8) + (+1) − ( − 7) b (+7) − ( − 1) − ( − 5) + (+3) + ( − 4) c ( − 5) + (+2) − ( − 4) − (+7) − ( − 1) E.8666 Perform the calculations below and give the result in simplified form : a − 2 3 + − 1 3 b + 4 5 + + 3 5 c − 3 7 − + 1 14 d + 2 3 − − 1 3 e − 9 4 + − 5 3 f + 8 3 − + 5 6 4. Reminders: simplified entries E.4343 Perform the following calculations : a 5 − 3 + 7 + 2 − 5 − 4 b − 2 − 3 + 4 − 8 + 5 c 3 − 8 − 10 + 4 + 7 d 11 − 24 + 12 − 11 E.1712 Rules: to simplify an expression containing additions and subtractions of relative numbers : Subtractions are turned into additions by changing the number following the subtraction into its opposite, Parentheses and ˇ + ı addition signs are not written in the simplified expression, If the first number of the operation is positive, we write not its sign ˇ+ı at the beginning of the expression For each expression, four simplified forms are proposed, but only one is correct. Copy the correct simplified form and calculate the expression : 1 (+2) − (+8) − ( − 4) + ( − 3) : a 2 − 8 − 4 − 3 b 2 − 8 − 4 − 3 c 2 + 8 + 4 + 3 d 2 − 8 + 4 − 3 2 ( − 7) − ( − 3) + (+5) − (+4) : a 7 + 3 + 5 − 4 b − 7 − 3 + 5 − 4 c − 7 − 3 + 5 − 4 d − 7 + 3 + 5 − 4 E.8667 Perform the calculations below : a 0.8 + 2.5 − 7.3 − 0.5 b − 0.2 + 1.5 − 2.7 + 0.3 c − 1.8 − 0.5 + 1.2 d 5.4 − 5.9 + 5.5 − 5.3 E.8668 Perform the calculations below and give the result in simplified form : a − 1 3 + 5 3 − 4 3 + 2 3 b 3 4 + 5 2 − 11 8 − 7 4 c − 2 3 − 5 4 + 1 6 + 1 3 d 5 4 − 1 3 + 1 9 − 11 6 5. Reminders: sum and priority of operations E.1175 Perform the following calculations : a − 2 − 3 + ( − 5 + 2) b 2 − (5 − 2 − 4) + 1 c 2 − 4 − 9 + 4 + 7 d (7 − 12) − (5 − 12 + 8) E.1713 Perform the following calculations : a 2 − 7 + 5 − 4 − 9 b 2 + 3 − (5 − 9) c − 2 + 9 − (3 + 7) d (3 + 2) + 3 − (4 − 7) − 2 E.4385 Perform the following calculations : a 5 − 4 − 3 + 2 − 1 b 15 − 3 + 5 − 7 c 15 − (3 − 8) d − (5 + 3) + (8 − 13) E. 8688 Perform the calculations below : a 2 − 5 + ( − 7 + 2) b − − 5+2 + − 8+3 − 7 E.1776 Perform the following calculations : a 3 − (5 − 8) b 2 + ( − 3 − 8) − (2 × 3 − 9) c − 3 − (9 − 2 × 10) d 5 − 4 − (9 − 12) E.1714 Correctly fill in the dotted lines with the missing relative number: a ( : : : ) + 2 = − 5 b 13 − ( : : : ) = 15 c 2.1 + ( : : : ) = 1.9 d 23 + ( : : : ) = 21.5 e ( : : : ) + 9.4 − 5 = 4 f 3 + ( : : : ) − 4 + 7 = − 3 https://chingmath.fr chapExoCorrec/1711 sacados/1711 chapExoCorrec/8665 sacados/8665 chapExoCorrec/8686 sacados/8686 chapExoCorrec/8666 sacados/8666 chapExoCorrec/4343 sacados/4343 chapExoCorrec/1712 sacados/1712 chapExoCorrec/8667 sacados/8667 chapExoCorrec/8668 sacados/8668 chapExoCorrec/1175 sacados/1175 chapExoCorrec/1713 sacados/1713 chapExoCorrec/4385 sacados/4385 chapExoCorrec/8688 sacados/8688 chapExoCorrec/1776 sacados/1776 chapExoCorrec/1714 sacados/1714
6. Multiplications E.1710 1 Determine the value of the product 7 × ( − 3) knowing that : 7 × ( − 3) = ( − 3) + ( − 3) + ( − 3) + ( − 3) + ( − 3) + ( − 3) + ( − 3) 2 Let’s find the result of the product ( − 7) × 3 : a Complete the extract from the multiplication table by 7: 17 18 19 20 21 22 23 24 × 7 140 ←−−−−− − : : : : : : −−−−−−→ + : : : : : : -4 -3 -2 -1 0 1 2 3 × 7 14 ←−−−−− − : : : : : : −−−−−→ + : : : : : : b Complete the following two sentences : The product of two positive numbers is a number of signs . . . . . . . . . . . . The product of a positive number and a negative number is a number of signs . . . . . . . . . . . . 3 Perform the following calculations : a 3 × 7 b 10 × ( − 4) c ( − 5) × 7 d 7 × 9 e 3 × ( − 8) f ( − 4) × 9 4 a Complete the table below, starting with the opera-tion 3 × ( − 7) : -3 -2 − 1 0 1 2 3 4 × ( − 7) ←−−−− ...... −−−−→ ...... b Complete the following sentences : The product of two negative numbers is a number of signs . . . . . . . . . . . . 5 Perform the following calculations : a 5 × ( − 4) b ( − 3) × 12 c ( − 4) × ( − 8) d 9 × 5 e 31 × ( − 3) f ( − 21) × ( − 2) E. 1724 Rule for multiplying relative numbers: The product of two relative numbers : is of sign : positive: if both factors are of the same sign, negative: if the two factors are of opposite signs. ’s distance to zero is the product of the distances to zero of the two factors Perform the following multiplications: a ( − 2) × 3 b − 4 × ( − 3) c (+2.5) × ( − 5) d ( − 2.4) × ( − 1.5) E.1024 Copy and complete this double entry table : × − 5 +2 − 1.4 3 − 5 +20 E.8669 Perform the calculations below, giv-ing the results in simplified forms : a 5 4 × − 6 7 b − 36 7 × − 21 8 c 1 3 × 5 7 d − 7 9 × 3 14 7. Multiplications of several factors E.1023 Proposal: To determine the sign of a product of several relative numbers, use the following rule : If the number of negative factors is even, then the prod-uct is positive. If the number of negative factors is odd, then the prod-uct is negative. Give the sign of each of the following calculations : a ( − 1) × ( − 1) × ( − 1) b ( − 1) × ( − 1) × ( − 1) × ( − 1) c ( − 1) × ( − 1) × (+1) × ( − 1) d (+1) × ( − 1) × (+1) × (+1) × ( − 1) × ( − 1) × (+1) × ( − 1) × ( − 1) × (+1) × (+1) × ( − 1) https://chingmath.fr chapExoCorrec/1710 sacados/1710 chapExoCorrec/1724 sacados/1724 chapExoCorrec/1024 sacados/1024 chapExoCorrec/8669 sacados/8669 chapExoCorrec/1023 sacados/1023
E. 1729 Determine the sign of the following expressions : a ( − 1) × (+1) × ( − 1) × ( − 1) × (+1) b ( − 2) × ( − 4) × ( − 4) × 2 × ( − 0.5) c ( − 3) × ( − 2) + (+5) × ( − 2) d ( − 1) × ( − 2) × (5) × (+2) × ( − 3) E.1739 Perform the following multiplica-tions : a − 3 × ( − 2) × 5 × ( − 3) b 5 × ( − 1) × (+10) × ( − 0.1) c 2 × ( − 8) × 0.5 × ( − 3) d ( − 4) × 5 × 2 × 0.25 E.1025 By choosing the factors cleverly, per-form the following calculations : a (+4) × ( − 0.1) × 10 × ( − 1) × 0.25 b − 5 × 0.1 × ( − 4) × ( − 5) × 4 × ( − 2) × 3 E.4387 Say whether the statements below are true or false : 1 The sum of two relative integers is positive. 2 The sum of 102 negative numbers is negative. 3 The product of 102 negative numbers is negative. 4 The opposite of a product is the product of the opposite of its factors. 8. Multiplication and sums E. 8672 Perform the calculations below : a ( − 2) × (+4) × ( − 5) b ( − 10) × (+1) × ( − 2) × ( − 5) c − 5 + 2 × ( − 3) d 2 − 2 × ( − 2) E.1013 Perform the calculations below : a − 3 + 5 × ( − 2) b ( − 6) × ( − 2) − 5 c − 2 + 5 − 4 × 2 d 4 × ( − 5) − 5 E.8673 A − 5 + 3 × ( − 2) b − 4 × ( − 5) + 2 c − 3 + ( − 2) × 5 d 14 − 5 × ( − 2) e 3 − 2 × 5 f − 2 × 3 − 3 E.1027 In each of the calculations below, a number has been hidden. Knowing the sign of the result, is it possible to find the sign of the hidden number? If so, indicate the sign of this number. a ( − 5) ×♣× (+0.02) est positif b − (+9) ×♠× ( − 1.5) is negative c ( − 9) + is positive d ( − 3) − 2 is négatif e ( − 3) + 3 × ( − 2) 2 × est négatif E.1019 For each expression, a number has been hidden ; only its sign has been displayed. If possible, give the sign of the result of each expression : a ( − 3) × ( − 5) × (+ ) b − ( − ) × (+1.8) × ( − 0.1) c (+5) + (+ ) d (+3.2) + ( − ) e ( − 3) × (+ )+(+7) × ( − ) f 8 + ( + 1) × ( + 1) E.1774 Some of the numbers in the equa-tions below have been hidden. Copy the following equalities, completing them with the correct number: a ( − 2) × = 36 b ( − 7) × × ( − 0.5) = − 14 c × 2 + 3 = − 19 d × 2 − 7 × ( − 2) = − 2 E.1014 Complete, line by line, the table below using the values of a , b and c given : a b c a × b a × c a × b − a × c b + c a × ( b + c ) 3 − 2 5 4 1.25 − 2.5 − 3 − 2 4 1.2 4 6 E.1015 Complete the table below row by row using, in each case, the values of a and b given : a b a + b a − b ( a + b ) × ( a − b ) 3 − 2 − 5 − 7 − 3 − 2 − 1.5 2.5 https://chingmath.fr chapExoCorrec/1729 sacados/1729 chapExoCorrec/1739 sacados/1739 chapExoCorrec/1025 sacados/1025 chapExoCorrec/4387 sacados/4387 chapExoCorrec/8672 sacados/8672 chapExoCorrec/1013 sacados/1013 chapExoCorrec/8673 sacados/8673 chapExoCorrec/1027 sacados/1027 chapExoCorrec/1019 sacados/1019 chapExoCorrec/1774 sacados/1774 chapExoCorrec/1014 sacados/1014 chapExoCorrec/1015 sacados/1015
9. Conducting calculations E. 8802 Method : To correctly process priority opera-tions one after the other, proper ˇ calculation ı is necessary. Watch the animation opposite : Perform the following calculations, detailing the steps in your reasoning : a 5 − 2 × 3 − 5 b 2 − 3 × 5 − 4 × 2) c 2 − 2 × 2 × 4 − 7 d − 4 × 2 × ( − 2) − 3 × ( − 4) E.1723 Perform the following calculations : a (9 − 13) × ( − 2) b (7 − 12) × ( − 8 + 4) c − (2 − 2 × 4) + 4 d 5 − ( − 2 − 3) e ( − 3 + 5) × ( − 5 − 7) f 5 − 2 × ( − 3 + 5) Indications : we will indicate the cal-culation steps respecting the priorities of the operations as in the example op-posite : E.1740 Perform the following calculations : a − 3 − ( − 7 + 5) × ( − 0.5) b − 2 + 3 × (5 − 3 × 5) c (2 − 3) 4 + ( − 2) ( − 3 − 4) d − 3 × 2 − ( − 2) × ( − 4) e − 2 − 3 × ( − 3) × ( − 2) + 5 E.1026 Perform the following calculations : a 30 − 2 + ( − 4) × 3 b ( − 2) × 5 − ( − 3) × ( − 2) c (50 − 62) × (5 − 4) d 2 × ( − 4) − 5 × 3 × 2 − 10 × 2.5 Hint: calculations will be conducted with wording similar to : E. 1028 Perform the following calculations : a ( − 3) × 3 − (+5) b 4 − 5 × ( − 2) + ( − 2) c − 4 × 3 + ( − 4) × − 2 − ( − 3) E. 8689 Perform the calculations below : a 3 − 2 × 2 + 3 × ( − 2) b 2 × 3 − 8 − 8 − 8 × 2 E.8671 Perform the following calculations : a 3 + ( − 5) × 2 × ( − 1) b 4.1 − 2 × ( − 1.2) × 6.8 − 7.1 c (5 − 2 × 3) − 2 × 7 − 4 × (2 × 3 − 8) E.4386 Perform the following calculations : a 15 − 8 + 3 × ( − 2) b (8 − 15) × − 12 − ( − 2) × 5 c (5 − 8) × − 12 − 5 × ( − 3) × 5 − 2 × 2 × ( − 6) + 10 E.1778 On each of the expressions below, the parentheses have been deleted ; add, if necessary, the paren-theses and brackets necessary to verify the proposed equali-ties : a 3 − 2 − 3 × 2 − 4 = 4 b 3 − 2 − 3 × 2 − 4 = − 3 c 3 − 2 − 3 × 2 − 4 = − 1 d 3 − 2 − 3 × 2 − 4 = − 9 E.6139 Calculations have been made but the brackets and braces have been removed. Copy the calcu-lations on your copy, adding, if necessary, the correctly placed brackets and braces : a 2 − 3 + 2 × 2 = − 8 b 2 − 3 + 2 × 2 = 3 10. Quotients E.1747 Rule: The sign of a quotient is : positive if numerator and denominator are of the same sign negative if numerator and denominator have opposite signs. Give the sign of each of the following calculations : a ( − 3) ÷ ( − 2) b 2 ÷ ( − 1) c ( − 3) ÷ 5 d − 5 − 8 e − 3 5 f 5 − 7 E. 4344 Write the fractions below in their simplified forms : a − 6 2 b 15 6 c − 4 − 16 d 21 − 14 e − 3 5 f − 150 − 100 E.4463 Perform the following calculations : a − 13 − 8 b 6 × ( − 3) c 5 − 13 d − 2 × ( − 5) e − − 24 8 f 12 − 3 https://chingmath.fr chapExoCorrec/8802 sacados/8802 qb6a chapExoCorrec/1723 sacados/1723 chapExoCorrec/1740 sacados/1740 chapExoCorrec/1026 sacados/1026 chapExoCorrec/1028 sacados/1028 chapExoCorrec/8689 sacados/8689 chapExoCorrec/8671 sacados/8671 chapExoCorrec/4386 sacados/4386 chapExoCorrec/1778 sacados/1778 chapExoCorrec/6139 sacados/6139 chapExoCorrec/1747 sacados/1747 chapExoCorrec/4344 sacados/4344 chapExoCorrec/4463 sacados/4463
E.6138 Here is a calculation diagram: Without justification, give the value of the number that must be present in the box with the sign ˇ ? ı in order for all calcu-lations to be correct. 11. Quotients and operations E.4345 Calculate the expressions below and write their values as decimals : a 7 + 15 − 3 b 3 − 8 − 2 − ( − 22) c 5 − 7 − 8 + 3 E.4464 Perform the following calculations : a 2 × ( − 5) − 4 3 − 5 b 7 − 5 4 × 7 − 30 E.8674 Perform the following calculations : a (3 × 2 − 5) ÷ (2 − 2 × 2) b − 3 × ( − 2) + 4 5 − 3 × 2 Note: calculations will be conducted with word-ing similar to : E.8676 Perform the following calculations and give the results in simplified form : a 5 × 2 − 7 5 − 8 b 3 × ( − 2) + 4 3 − 3 × 3 c 5 − 2 × 3 5 × 6 d 5 − 36 ÷ 6 60 − 8 × 7 E.4383 Perform the following calculations and give the results in simplified form : a 2 − 5 − 3 × (2 − 4) 2 − 15 ÷ 5 b 12 × 3 − 6 × 6 3 − 2 − (2 × 5 − 12) Indication : calcula-tions will be conducted with wording similar to : 12. Squares of relative numbers E.1017 Definition: le The square of a number is that number multiplied by itself. The square of the number x is written as x 2 . Example: 3 2 =3 × 3=9 ( − 2) 2 =( − 2) × ( − 2)=4 Note: the expression − 5 2 is the opposite of the square of 5 and equals − 25 . Example: − 3 2 = − 9 ; ( − 3) 2 =9 Perform the following calculations : a 3 2 b ( − 3) 2 c − 3 2 d 5 2 e ( − 5) 2 f − 5 2 E.8675 A 2 × 9 2 b − 2 × 4 2 c ( − 2 × 4) 2 d − ( − 2) 2 e 2 2 − 5 2 E.1029 Perform the following calculations : a − 5 2 b 2 × ( − 4) 2 c 3 × ( − 2) 2 d − 3 × ( − 2) 2 e 2 − 3 2 f − (2 − 3) 2 E.1018 Perform the following calculations : A 2 × 6 2 b − 2 × 3 2 c ( − 3 × 5) 2 d − ( − 9) 2 e 7 2 − 2 2 E.1741 Perform the following calculations : a ( − 3) 2 × 2 − 13 b (2 × 3 − 7) 2 + 2 2 c − 3 2 × (3 − 2 × 5) d 5 2 − 9 2 e (2 − 3) 2 − ( − 3) 2 f 2 × 5 − 3 2 2 Note: calculations will be con-ducted with wording similar to : https://chingmath.fr chapExoCorrec/6138 sacados/6138 ×÷−1-3-2-29-32?−×-2 chapExoCorrec/4345 sacados/4345 chapExoCorrec/4464 sacados/4464 chapExoCorrec/8674 sacados/8674 chapExoCorrec/8676 sacados/8676 chapExoCorrec/4383 sacados/4383 chapExoCorrec/1017 sacados/1017 chapExoCorrec/8675 sacados/8675 chapExoCorrec/1029 sacados/1029 chapExoCorrec/1018 sacados/1018 chapExoCorrec/1741 sacados/1741
E.8690 Perform the calculations below : a 12 − 2 × 3 2 2 b 1 + 3 2 2 − 9 2 E.1777 Perform the following calculations : a ( − 8 + 2 × 3) 2 b (3 − 6) 2 × ( − 2) c − 2 − ( − 3) 2 2 d (5 − 9) 2 − 3 2 2 13. Literal expressions and relative numbers E. 1730 Consider the following equality: 3 x − 7=2 x − 11 Test the previous equality using the following values : a x = − 1 b x =3 c x = − 4 E.1775 Consider the following two algebraic expressions : A = − 3 x + 1 ; B = − x 2 − 5 x + 4 Evaluate each of these expressions for the values : x = 1 ; x = − 3 ; x = 0 E.8678 Consider the expression : C = − (3 − x ) 2 +2 x +1 Evaluate this expression for the values : a x = 5 b x = − 2 E.1020 We consider the two literal expres-sions : A = 2 x 2 + 3 x − 10 ; B = − x 2 + 4 x + 42 1 Prove the equality of these two expressions for x = − 4 . 2 Test the equality of these two expressions for x =2 . E.1030 Consider the following literal expres-sions : A = − x 2 + 4 x − 5 ; B = (12 − x ) 2 + 5 C = (2 x − 9)(3 − x ) 1 Evaluate the literal expression A for x =6 . 2 What is the value of the literal expression B for x =15 ? 3 Evaluate the literal expression C for x =3 . E.8677 Evaluate the expression C = − (2+ x ) 2 +2 x +1 for the values : a x = 5 b x = − 2 E.1022 We consider the two literal expres-sions : A = − 2 x 2 + 2 ; B = (2 x 2 − 2)(2 x + 3) 1 Prove the equality of A and B for x = − 2 . 2 Test this equality for x =2 . 14. Calculation sheet and calculation program E.8684 The following spreadsheet is used : After entering the formula ˇ 3 × A1-4 ı in cell A2 , extend this formula to the right. Complete the table to show the results. E.8681 The following calculation pro-gram is given : Choose a number Add 1 Square the result Subtract the square of the starting number from the re-sult. 1 Show that when we choose the number 2 at the start, we get the number 5 at the end. 2 What result do we get when we choose the number − 3 at the start? E.8680 We consider the calculation program : Choose a number Take the square of this number Add triple the starting number Add 2 1 Show that if we choose 1 as the starting number, the program gives 6 as the result. 2 What result do we get if we choose − 5 as the starting number? 3 We call x the starting number, express the result of the program in terms of x . 4 Consider the worksheet below : a Complete the worksheet. b Which formula was written in cell B2 before extending it to cell J2 ? https://chingmath.fr chapExoCorrec/8690 sacados/8690 chapExoCorrec/1777 sacados/1777 chapExoCorrec/1730 sacados/1730 chapExoCorrec/1775 sacados/1775 chapExoCorrec/8678 sacados/8678 chapExoCorrec/1020 sacados/1020 chapExoCorrec/1030 sacados/1030 chapExoCorrec/8677 sacados/8677 chapExoCorrec/1022 sacados/1022 chapExoCorrec/8684 sacados/8684 fx12ABCDEF-3-2-1012-13A2×A1−4 chapExoCorrec/8681 sacados/8681 chapExoCorrec/8680 sacados/8680 12ABCDEFx−5−1013x2×x21220
E.8685 Laura created three variables and then made the script below : 1 Check that if the value of x is 5 then the result is 63 . 2 What result do we get if the value of x is − 3 ? 3 Of the following expressions, copy the one that matches the calculation program given by the script. x + 4 × 2 x − 3 x + 4 × 2 x − 3 x + 4 × 2 x − 3 15. Share E.8729 Calculate the following expressions by detailing the steps : a 9 − 15 + 2 − 7 b 4 × ( − 2) × ( − 3) c − 8 + 2 × ( − 2) d 5 − 7 − 3 + 5 e 5 + 3 × 7 − 3 × 5 E.8730 Calculate the following expressions by detailing the steps : a 8 − 10 + 4 − 11 b 3 × ( − 3) × ( − 2) c 8 + ( − 4) × ( − 2) d 4 − 7 − 3 + 5 e 5 + 2 × 5 − 4 × 5 E.8776 Perform the calculations : a 5 − 2 × 5 b ( − 3) × 2 + ( − 2) × ( − 5) c 2 − 1 − 3 × (3 − 5) E.8788 Perform the following calculations, de-tailing the steps : a − 4 × 3 − 3 × ( − 2) b − 2 × 5 − 2 × 3 − 3 16. Unclassified exercises E.2086 Compare the following fractions : a 3 7 : : : 3 8 b − 9 4 : : : − 11 4 c 6 7 : : : 13 12 d 2 6 : : : 2 4 e 3 7 : : : 2 5 f 7 3 : : : 9 4 https://chingmath.fr chapExoCorrec/8685 sacados/8685 Etape 1Etape 2xCréer une variablequandest cliquédemandervaleur dex?et attendremettrexàréponsemettreEtape 1àx+4mettreEtape 2à2*x-3direregroupeLe résultat estEtape 1*Etape 2 chapExoCorrec/8729 sacados/8729 chapExoCorrec/8730 sacados/8730 chapExoCorrec/8776 sacados/8776 chapExoCorrec/8788 sacados/8788 chapExoCorrec/2086 sacados/2086