aidez moi svp ex 24 merci beaucoup

bonjour

a = 3a
b =  b
c =  8b²
d = 6b -3
e = 21ab
f = 6 a au cube

Bonsoir,

A = 3 x a
A = 3a

B = 1 x b
B = b

C = 8 x b x b
C = 8b²

D = 3 x (2 x b - 1)
D = 3 x (2b - 1)
D = 6b - 3

E = 7 x a x 3 x b
E = 21ab

F = a x 6 x a x a
F = 6a³