Réponse :
bonjour
A = - 2 /21 x 14/5 - 8 /5
= - 2 / 3 x 2 /5 - 8 /5
= - 4 /15 - 24/15
= - 28 /15
B = 1/4 + 5/3 x - 1/8
= 1/4 - 5/24
= 6/24 - 5 /24
= 1 /24
C = 4 /- 3 - 7 /6 x - 2 /5
= - 4/3 + 14 /30
= - 4 /3 + 7/15
= - 20/15 + 7 /15
= - 13 /15
D = ( 8 /15 - 7/15 ) ( - 1 /6 + 2 /9 )
= 1 /15 x ( - 3 /15 + 4 /18 )
= 1 /15 x 1 /18
= 1 / 270
Explications étape par étape :
