Réponse:
bonjour
Explications étape par étape:
A = -3 (5x - 4)
= -3 × 5x + 3×4
= -15x + 12
B = (2x - 8)(4x - 7)
= 2x × 4x -2x × 7 - 8 × 4x + 8×7
= 8x² -14x -32x +56
= 8x² -46x +56
C = x - (x+7)(5x - 3)
= x - (x×5x - x × 3 + 7 ×5x - 3×7)
= x - (5x² -3x + 35x -21)
= x - (5x² +32x -21)
= x - 5x² -32x +21
= -5x² -31x +21
