Je n'y arrive pas, aidez-moi..

A = (2 + 5x) (3 + 7x)
A = 2 * 3 + 2 * 7x + 5x * 3 + 5x * 7x
A = 6 + 14x + 15x + 35x²
A = 6 + 29x + 35x²

B = (3y - 5) (2y + 7)
B = 3y * 2y + 3y * 7 - 5 * 2y - 5 * 7
B = 6y² + 21y - 10y - 35
B = 6y² + 11y - 35

A=(2+5x) (3+7x) A=2×3+2×7x+5x×3+5x×7x A=6+14x+15x+35x² A=6+29x+35x²