73)
A =3x -3 =3( x-1);B = 4x +6 = 2(2x +3); C= 8+2x = 2 ( 4+x) ; D = 7y² -5y = y (7y -5);
E = 30a +36a² = 6a ( 5 +6a) ; F = -9x² -9 = 9 ( -x² -1)
74)
A = (x -2) ( x+3) + (x-2)(x+6)
(x- 2 ) (x+3 + x+6)
( x-2) (2x +9)
B = ( x+5)(4x-2) - (x-5)(9x+1)
= (x + 5) ( 4x - 2 - 9x -1)
= (x +5) ( -5x -3)
C = (3x+8)² - (6x-7)(3x+8)
= (3x+8) (1- 6x +7)
= (3x +8) (-6x +8)
j'espère ça peut t'aider ..
