bonjour
1 ) A = - 8 a² b
B = 5 x - x²
C = 3 x - 1 + 2 x = 5 x - 1
2 ) D 2 x ( 4 x - 5 ) = 8 x² - 10 x
E . - 4 ( 3 x - 1 ) - 5 x ( 7 x - 6 )
= - 12 x + 4 - 35 x² + 30 x = - 35 x² + 18 x + 4
F ) ( 4 x + 7 ) ( 5 x - 3 )
= 20 x² - 12 x + 35 x - 21
= 20 x² + 23 x - 21
G ) x² -16 = ( x - 4 ) ( x + 4 )
H ( x+ 3 ) ( x + 2) + x + 2 = ( x + 3 ) ( x + 2 ) + 1 ( x + 2 )
= ( x + 2 ) ( x + 3 + 1 )
= ( x + 2 ) ( x + 4 )
I ( x - 3 ) ( x + 2) - ( x + 2 ) ( 3 x - 5 )
= ( x + 2 ) ( x - 3 - 3 x + 5 )
= ( x + 2 ) ( - 2 x + 2 )
