Bonjour ;
Exercice n° 35 .
a.
(- 7)/25 x (- 5)/8
= 7/25 x 5/8
= 5/25 x 7/8
= 1/5 x 7/8
= (1 x 7)/(5 x 8)
= 7/40 .
b.
18/(- 49) x 14/27
= - 18/49 x 14/27
= - 18/27 x 14/49
= - 2/3 x 2/7
= - (2 x 2)/(3 x 7)
= - 4/21 .
c.
45/28 x 7/(- 15)
= - 45/28 x 7/15
= - 45/15 x 7/28
= - 3/1 x 1/4
= - (3 x 1)/(1 x 4)
= - 3/4 .
d.
(- 2)/6 x (- 21)/11
= 2/6 x 21/11
= 1/3 x 21/11
= 21/3 x 1/11
= 7/1 x 1/11
= (7 x 1)/(1 x 11)
= 7/11 .
e.
21/32 x 108/49
= 21/49 x 108/32
= 3/7 x 27/8
= (3 x 27)/(7 x 8)
= 81/56 .
f.
- 26 x (- 5)/39
= 26 x 5/39
= 5 x 26/39
= 5 x 2/3
= 5/1 x 2/3
= (5 x 2)/(1 x 3)
= 10/3 .
g.
8/5 x (- 5)/21
= - 8/5 x 5/21
= - 5/5 x 8/21
= - 1 x 8/21
= - 8/21 .
h.
56/(- 5) x 30/21 x 7/10
= - 56/5 x 30/21 x 7/10
= - 56/5 x 30/10 x 7/21
= - 56/5 x 3 x 1/3
= - 56/5 x 1
= - 56/5 .
