bonjour pouvez vous m aider ex 2 merci bcp

bjr

1 => cf définition cours

2

5(6b+3) = 5*6b + 5*3 = 30b + 15

9y(7y-4) = 9y*7y - 9y*(-4) = 63y² + 36y

-2(8-m) = -2*8 - 2*(-m) = -16 + 2m

12a - 18 = 6*2*a - 9*2 = 2(6a-9)

20c+4c² = 4c*5 + 4c*c = 4c(5+c)

7 + 21k = 7*1 + 7*3k = 7(  ... + ... )

3)

a = 3*(-4) - 4(5-4) = -12 - 4 = - 16

b = x(82+33+18+67) = 200x = 200*(-0,08) = -16

c = -6x - 18 - 4x + 18 = -10x = -10*1,6 = -16