Bonjour pouvez vous m'aidez svp: Développer et réduire : A = (x + 5)(x + 3) B = (3x – 2)(x + 4) C = (y + 3)(y – 2) D = (z – 4)(z – 1) mercid'avance

A = x × x + x × 3 + 5 × x + 5 × 3

A= x² + 3x + 5x + 15

A = x² + 8x + 15

B = 3x × x + 3x × 4 -2 × x -2 × 4

B = 3x² + 12x - 2x - 8

B = 3x² + 10x - 8

C = y × y + y × (-2) + 3 × y + 3 × (-2)

C = y² -2y + 3y - 6

C = y² + y - 6

D = z × z + z × (-1) - 4 × z - 4 × (-1)

D = z² - z - 4z + 4

D = z² - 5z + 4

Hello,

(x + 5)(x + 3) = x * x + x * 3 + 5 * x + 5 * 3 = x² + 3x + 5x + 15 = x² + 8x + 15

(3x - 2)(x + 4) = 3x * x + 3x * 4 - 2 * x - 2 * 4 = 3x² + 12x - 2x - 8 = 3x² + 10x - 8

(y + 3)(y - 2) = y * y + y * -2 + 3 * y + 3 * -2 = y² - 2y + 3y - 6 = y² + y - 6

(z - 4)(z - 1) = z * z + z * -1 - 4 * z -4 * -1 = z² - z - 4z + 4 = z² -5z + 4