Grade 8
/ Arithmetic 16 exercises (100% corrected)
- Number of divisors (5 exercices)
- First integers (3 exercices)
- Decomposition of an integer into a product of prime numbers (5 exercices)
- Simplification of fractions (3 exercices)
722×36722×2×18722×2×2×9722×2×2×3×3
E.9079
Definition:
an
integer
is
said
to
be
decomposed
into
a
product
of
prime
integers
if
it
is
written
as
a
product
whose
factors
are
all
prime
integers.
Example:
the
integer
72
admits
the
decomposition
:
2
×
2
×
2
×
3
×
3
Algorithm
:
opposite
is
a
method
of
obtaining
the
decomposition
of
an
inte-ger
into
a
product
of
prime
integers
:
1
Use
the
equality
28=2
×
14
to
obtain
the
prime
product
decomposition
of
the
integer
28
.
2
Use
equality
40=2
×
20
to
obtain
the
prime
product
de-composition
of
the
integer
40
.
3
Use
equality
96=2
×
48
to
obtain
the
prime
product
de-composition
of
the
integer
96
.
E.9080
For
each
of
the
integers
198
,
297
,
462
,
determine
their
decomposition
into
a
product
of
primes.
Hints:
for
this,
use
the
equalities:
198
=
6
×
33
297
=
9
×
33
462
=
14
×
33
E.9081
1
Justify
that
the
number
102
is
divisible
by
3
.
2
Decompose
102
into
products
of
prime
factors.
3
Give
3
nonprime
factors
of
the
number
102
.
E.9321
What
is
the
largest
prime
number
that
divides
41
895
?
E.9324
1
a
Determine
the
prime
factor
product
decomposition
of
2744
.
b
Determine
the
prime
factor
product
decomposition
of
2744
2
.
c
Using
this
decoposition,
find
x
such
that
:
x
3
=2744
2
2
Let
a
and
b
be
two
integers
greater
than
2
such
that
:
a
3
=
b
2
a
Calculate
b
when
a
=100
.
b
Determine
two
integers
a
and
b
greater
than
2
and
less
than
10
that
verify
the
equality
a
3
=
b
2
.
4.
Simplification
of
fractions
E.9082
1
Give
the
product
decomposition
of
the
prime
integers
of
the
integers
:
42
;
90
2
Derive
the
reduced
writing
of
the
fraction
42
90
.
E.9083
1
Decompose
140
and
870
into
the
product
of
primes.
2
Deduce
the
irreducible
form
of
the
fraction
140
870
E.9084
1
Decompose,
without
justification,
the
numbers
1
386
and
1
716
into
products
of
prime
factors.
2
Deduce
the
irreducible
form
of
the
fraction
:
1
386
1
716
https://chingmath.fr
chapExoCorrec/9079
sacados/9079
722×36722×2×18722×2×2×9722×2×2×3×3
chapExoCorrec/9080
sacados/9080
chapExoCorrec/9081
sacados/9081
chapExoCorrec/9321
sacados/9321
chapExoCorrec/9324
sacados/9324
chapExoCorrec/9082
sacados/9082
chapExoCorrec/9083
sacados/9083
chapExoCorrec/9084
sacados/9084