Suite exercice 3 :
A = (w-2)^2
= (w-2)(w-2)
= w x w - w x 2 - 2 x w + 2 x 2
= w^2 - 2w - 2w + 4
= w^2 - 4w + 4
B = (3+m)(m-3)
= 3 x m - 3 x 3 + m x m - m x 3
= 3m - 9 + m^2 - 3m
= m^2 - 9
C = (5u+6)(5u-6)
= 5u x 5u - 5u x 6 + 6 x 5u - 6 x 6
= 5u^2 - 30u + 30u - 36
= 5u^2 - 36
Exercice 4 :
A = 3(X-2) + (3-2X)(3+2X)
= 3X - 6 + 9 - 4X^2
= - 4X^2 + 3X + 3
B = (3-X)^2 + (X+5)^2
= 9 - 6X + X^2 + X^2 + 10X + 25
= 2X^2 + 4X + 34
C = (X+1)(X-1) + (X+4)2
= X^2 - 1 + X^2 + 8X + 16
= 2X^2 + 8X + 15
D = (X+5)(2X+3) + (2X+7)(2X-7)
= 2X^2 + 3X + 10X + 15 + 4X^2 - 49
= 6X^2 + 13X - 34
