Bonjour,
Développer :
1) 7x + 6 - 6 (4x + 8)
= 7x + 6 - 24x - 48
= 7x - 24x + 6 - 48
= - 17x - 42
2) 81x² + 144x + 64
= (9x + 8)²
9x + 8 = 0
9x = - 8
x = - 8/9
3) -16x -2
= - 2 (8x + 1)
4)(8x−6)x+x(−2x+2)
= 8x² - 6x - 2x² + 2x
= 6x² - 4x
5)(7x−6)x−7x
= 7x² - 6x - 7x
= 7x² - 13x.