Grade 9 / Literal expressions 49 exercises corrected

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ChingQuizz : 3 exercises available for Quizz assessment : 1. Reminders E.3588 Consider the following calculation program : Choose a starting number. Add 1 . Calculate the square of the result obtained. Subtract the square of the starting number from it. Write down the final result. 1 Check that when the starting number is 1 , the final result is 3 . 2 When the starting number is 2 , what is the final result? 3 With the starting number being x , express the final result in terms of x . E.3587 1 Determine, for each of the above segments, an expression for their lengths as a function of x . 2 Give the length of each of these segments when x =5 . E.3694 Students in 3 ième were asked the following question : ˇEst it true that, for any value of the number x , we have : 5 x 2 − 10 x + 2 = 7 x − 4 ı Lea replied : ˇ Yes, that is true. Indeed, if we replace x with 3 , we have : 5 × 3 2 − 10 × 3+2=17 and 7 × 3 − 4=17 ı Myriam replied : ˇNo, this is not true. In fact, if we re-place x with 0 , we have : 5 × 0 2 − 10 × 0+2=2 and 7 × 0 − 4= − 4 ı One of these two students has given an argument that cor-rectly answers the question posed in the exercise. State which one by explaining why. E.3762 The following calculation pro-gram is given : Choose a number. Multiply that number by 3 . Add the square of the chosen number. Multiply by 2 . Write the result. 1 Show that, if we choose the number 10 , the result ob-tained is 260 . 2 Calculate the exact value of the result obtained when : The number chosen is − 5 ; the chosen number is 2 5 . E.3603 For each of the two cases below find the literal expression that was entered into the calculator to obtain the following table : 1 Valeur de x Résultat affiché 1 7 2 12 3 17 4 22 2 Valeur de x Résultat affiché 1 20 2 13 3 6 4 -1 E.3638 We consider the following three lit-eral expressions : A =8 x − 8 ; B =3(3 x − 4) − x +4 ; C =( x − 1)(2 x +4) 1 a Evaluate these three expressions for the different val-ues of x proposed : A B C x = 1 x = 2 x = 0 b Can we say that the expressions A and B are equal? Can we say that the expressions B and C are equal? 2 a Give the expanded and reduced form of the expres-sions A and B . b What can we conclude about the expressions A and B ? E.688 Determine the reduced expression of each of the following expressions : A = x + 3 4 − 3 x − 2 4 ; B = 2 x + 5 3 + x − 2 2 https://chingmath.fr quizzChap/1044 chapExoCorrec/3588 sacados/3588 chapExoCorrec/3587 sacados/3587 ABx7cm DCx12cm EFx2x1cm1cm chapExoCorrec/3694 sacados/3694 France Septembre 2008 chapExoCorrec/3762 sacados/3762 chapExoCorrec/3603 sacados/3603 chapExoCorrec/3638 sacados/3638 chapExoCorrec/688 sacados/688
E.2228 Give each of the expressions below in their simplest form : a 3 x − 2 5 − − 7 − 2 x 5 b 2 x − 1 3 + x + 1 4 2. Reminders: simple distributivity E.9154 Develop and simplify expressions : a 3 × ( x + 2) b 5 × (2 x − 1) e 3 × (4 x − 1) E. 3604 Expand and reduce each of the following expressions : a 2 x − 2 + 3 x + 2 b 4 1 − x + 3 x + 1 E.9200 Expand and then reduce each of the following expressions : E.11543 Expand and then reduce each of the following expressions : E. 11372 Develop and simplify expressions : a 2 × (6 + x + 2) b 3 × 5 + 2 x + 3 x E.10808 Expand and reduce the following expression : A = 3 2 x − 5 − 4 × (3 x − 2 E.9195 Expand and reduce the following expressions : a 3(2 x − 1) − 3(5 − 2 x ) b 2(1 − x ) − 6( x + 2) E.9196 Expand and then reduce each of the following expressions : E.2204 Expand and reduce the following expressions : a − ( x 2 − 3 x + 2) + 2(2 x + 1) b x (2 x − 1) − ( x 2 +11 x +2) c 2 x × (8 − x ) − 5 x × ( x +1) E.11369 Expand and simplify the expres-sions : a (2 x + 1) × 5 + 2 c 2 × (4 + x + 5) E.11370 Expand and simplify the expres-sions : a 2 × ( x − 1) + 8 × (3 x + 4) b 3 × ( x + 2) + 2 × (3 x − 1) E.11371 Expand and then reduce each of the following expressions : 3. Reminders: simple distributivity and factorization E.9197 Factor the following expressions : a 3 x + 6 b 16 x − 4 c 3 x + 9 E.5205 Factorize the expressions below (we will be led to reveal a factor common to the terms of the sum) : a 10 x − 15 b 14 x − 12 c − 6 x − 4 E.11493 Factorize the expressions below (we will be led to reveal a factor common to the terms of the sum) : a 6 x + 4 b 14 − 21 x c 15 x − 10 E.11544 Factor the following expressions using distributivity: a 4 x + 6 b x 2 + 3 x E.9202 Factor the following algebraic ex-pressions using distributivity: a 3 x + 5 x b 4 x 2 + 3 x c x 2 + 3 x E.10740 Factorize the expressions below (we will be led to reveal a factor common to the terms of the sum) : a 5 x 2 + 7 x b 10 x 2 + 7 x c 5 x + 3 x 2 E.10811 Factor the following expressions : a 7 x + 7 x 2 b 8 x 2 + 6 x c 6 x + 15 x 2 E.11492 Factor the following algebraic ex-pressions using distributivity: a x 2 x + 3) + 5 x 2 b 10 x + x ( x − 4) E.10741 Factor then reduce each of the fac-tors of the resulting expression : a 5 × x + 2 + 5 × 3 x + 1 b x × 4 x − 2 + x × x + 5 E.10742 Factor then reduce each of the fac-tors of the resulting expression : a x x − 2 − x 7 x − 5 b x 2 3 x + 2 − x 2 × 3 − x E.10958 Factor the following expressions : a x 3 x + 2 + x 5 − x b x 2 x + 1 − x 2 E.10960 Factor the following expressions : a 5 x 2 + 3 x − 4 x × y b 6 x 4 y + 1 + x 5 − y https://chingmath.fr chapExoCorrec/2228 sacados/2228 chapExoCorrec/9154 sacados/9154 chapExoCorrec/3604 sacados/3604 chapExoCorrec/9200 sacados/9200 chapExoCorrec/11543 sacados/11543 chapExoCorrec/11372 sacados/11372 chapExoCorrec/10808 sacados/10808 chapExoCorrec/9195 sacados/9195 chapExoCorrec/9196 sacados/9196 chapExoCorrec/2204 sacados/2204 chapExoCorrec/11369 sacados/11369 chapExoCorrec/11370 sacados/11370 chapExoCorrec/11371 sacados/11371 chapExoCorrec/9197 sacados/9197 chapExoCorrec/5205 sacados/5205 chapExoCorrec/11493 sacados/11493 chapExoCorrec/11544 sacados/11544 chapExoCorrec/9202 sacados/9202 chapExoCorrec/10740 sacados/10740 chapExoCorrec/10811 sacados/10811 chapExoCorrec/11492 sacados/11492 chapExoCorrec/10741 sacados/10741 chapExoCorrec/10742 sacados/10742 chapExoCorrec/10958 sacados/10958 chapExoCorrec/10960 sacados/10960
E.10790 Factor ˇ to the maximum ı the fol-lowing expressions : a 10 x + 5 x × 2 x + 1 b 15 x 4 × y 2 + 3 x 2 × y 5 E.10826 Determine the factorized form of each of the following expressions : a 12 x 2 + 15 x 2 x + 3 b 5 x 2 + 3 x 5 × y 2 4. Factoring E.686 We are going to factor the following expressions : a (2 x − 1)(3 x + 1) + (2 x − 1)(5 − 2 x ) c ( x − 3)(2 x + 2) + ( x − 3) x d 2( x − 1) − ( x − 1)(3 x + 3) 1 Each of the above expressions is a sum (or a difference) where each of its terms is a product. In each expression, underline the common factor of its two terms. 2 Noting k as the common factor and a , b as the other two factors, complete the table below : k a b a b c 3 Factor each of these expressions. Definition: The distributive property of multiplication over addition gives the two factorization formulas : k · a + k · b = k × ( a + b ) ; k · a − k · b = k × ( a − b ) E.10961 Factor the following expressions : a (2 x +1) × 2 + (2 x +1) × x 2 b (5 − 2 x ) × 2 + (5 − 2 x ) × x Hint: before you start factoring, you can underline the common factor present in each term of the expression. E.10959 Factor the following expressions : a (4 x + 3)(2 − 3 x ) − (2 − 3 x )( x − 1) b ( x + 1) 2 + ( x + 1)(2 x − 3) E.9203 Factor the following expressions : a 4(5 x + 2) + 2 x (5 x + 2) b (3 x + 2)2 x + 2 x (2 − x ) Hint: Before starting to factor, you can underline the com-mon factor present in each term of the expression. E.705 Factor the following expressions : a 5 x (1 − x ) + (5 x + 2)(1 − x ) b (3 x − 2)( x + 1) + (3 x − 2)(1 − x ) Indication : before starting the factorization, we can un-derline the common factor present in each of the terms of the expression. E.704 Factor the following expressions : a 3( x + 2) + ( x + 1)( x + 2) b (2 − x )( x +1) − (2 − x ) E.10962 Factor the following expressions : a (3 x − 4)(3 − 2 x ) − (3 − 2 x ) b (2 x +1)(5 x +1) − x (2 x +1) E.10964 Factor the following expressions : a (2 x − 1)( x + 1) + ( x + 5)( x + 1) b 3 x 2 x + 5 − 2 x + 5 x + 5 E.685 Factorize algebraic expressions : a (1 − 3 x )(2 + x ) + (1 − 3 x )(5 − 2 x ) b (2 + 3 x )( x − 1) − ( x + 1)(3 x + 2) E.9204 Factor the following expressions a ( x +1) 2 + ( x +1)(5 x − 4) b (9 x +1) 2 + (9 x +1)(1 − x ) E.10963 Factor the following expressions a (2 x + 3) 2 + 2 x + 3 b 5 x + 3 2 − 5 x − 3 5. Unclassified exercises E.6354 Alexandre on building a house of cards. He succeeded in building a 3 -storey castle. https://chingmath.fr chapExoCorrec/10790 sacados/10790 chapExoCorrec/10826 sacados/10826 chapExoCorrec/686 sacados/686 chapExoCorrec/10961 sacados/10961 chapExoCorrec/10959 sacados/10959 chapExoCorrec/9203 sacados/9203 chapExoCorrec/705 sacados/705 chapExoCorrec/704 sacados/704 chapExoCorrec/10962 sacados/10962 chapExoCorrec/10964 sacados/10964 chapExoCorrec/685 sacados/685 chapExoCorrec/9204 sacados/9204 chapExoCorrec/10963 sacados/10963 chapExoCorrec/6354 sacados/6354 1étage2étage3étage
Let n be a strictly positive integer. To find out the number of cards needed to build the castle with n floors, the following three expressions are proposed : a 5 n − 3 b 3 2 n 2 + 1 2 n c 2 n 2 − n + 1 Two of these expressions are not correct. Which two? E. 8978 The figure below gives a schematic of a calculation program. 1 If the starting number is 1 , show that the result is − 15 . 2 If we choose any number x as the starting number, which of the following expressions gives the result obtained by the calculation program? Justify. A = x 2 − 5 × 3 x +2 B =(2 x − 5)(3 x +2) C =2 x − 5 × 3 x +2 3 Lily claims that the expression : D =(3 x +2) 2 − ( x +7)(3 x +2) gives the same results as the expression B for all values of x . Is Lily’s statement true? Justify. E.8682 Here are two calculation pro-grams : 1 a Show that, if we choose the number 5 , the result of the program A is 29 . b What is the result of the program B if we choose the number 5 ? 2 If we name x the chosen number, explain why the result of the program A can be written x 2 +4 . 3 What is the result of the program B if we name x the chosen number? 4 Are the following statements true or false? Justify the answers and write the steps of any calculations : a ˇ If we choose the number 2 3 , the result of the program B is 58 9 . ı b ˇ If we choose an integer, the result of the program B is an odd integer. ı c ˇ The result of the program B is always a positive num-ber. ı d ˇ For the same chosen integer, the results of the pro-grams A and B are either both even-numbered integers, or both integers impairs ı E.682 Reduce expression A : A =2 × 3 x +1 4 − 1 − x 2 https://chingmath.fr chapExoCorrec/8978 sacados/8978 Choisir un nombreCalculer son tripleCalculer son doubleAjouter2Multiplier les deux nombres obtenusSoustraire5 chapExoCorrec/8682 sacados/8682 Brevet Antilles Guyanes Juin 2019 Programme AChoisir un nombreSoustraire 2Multiplier par4Elever au carréAjouter les deux nombresProgramme B•Choisir un nombre•Calculer son carré•Ajouter6au résultat chapExoCorrec/682 sacados/682