1: x(x+5)+x(3x-2) 2: (x+5)(2x+1)+6(2x+1) 3: -4x(2x+3)+(2x+3)(9x-2) 4 -8x(5x-1)-8x(12-x)

bonsoir

1) x² + 5 x + 3 x² - 2 x = 4 x² + 2 x 

2) 2 x² + x + 10 x + 5 + 12 x + 6 = 2 x² + 23 x + 11

3) - 8 x² - 12 + 18 x² - 4 x + 27 x - 6 = 10 x² + 23 x - 18

4) - 40 x² + 8 x - 96 x + 8 x = - 40 x²  - 80 x

1: x(x+5)+x(3x-2)= x² + 5x + 3x² - 2x
= x² + 3x² + 5x - 2x
= 4x² + 3x

2: (x+5)(2x+1)+6(2x+1)
= 2x² + x + 10x + 5 + 12x + 6
= 2x² + x + 10x + 12x + 5 + 6
= 2x² + 23x + 11

3: -4x(2x+3)+(2x+3)(9x-2)
= - 8x² - 12x + 18x² - 4x + 27x - 6
= - 8x² + 18x² - 12x - 4x + 27x - 6
= 10x² + 11x - 6

4 -8x(5x-1)-8x(12-x)
= - 40x² + 8x - 76x + 8x²
= - 40x² + 8x² + 8x - 76
= - 32x² - 68