bonsoir
x(x+1)-(-2x+2)(4-x)
=x² + x - ( - 8 x + 2 x² + 8 - 2 x )
= x² + x + 8 x - 2 x² - 8 + 2x
= - x² + 11 x - 8
2) (3-2x) (3x-1)+3 (x ² -2x)
= 9 x - 3 - 6 x² + 2 x + 3 x² - 6 x
= - 3 x² + 7 x - 3
3) 2(4x+7)(-2-5x)-x(x-2)
= 2 ( - 8 x - 20 x² - 14 - 35 x ) - x² + 2 x
= - 16 x - 40 x² - 28 - 70 x - x² + 2 x
= - 41 x² - 84 x - 28
