bonjour vous pouvez m’aidez svp

Bonjour,

I = (x + 1)(x + 5)

I = x² + 5x + x + 5

I = x² + 6x + 5

J = (4x + 5)(2x + 6)

J = 8x² + 24x + 10x + 30

J = 8x² + 34x + 30

K = (5u + 1)(2 - 3u)

K = 10u - 15u² + 2 - 3u

K = 10u + (-15u²) + 2 + (-3u)

K = 7u - 15u² + 2

L = (-3 + n)(-2n - 5)

L = 6n + 15 - 2n² - 5n

L = n + 15 - 2n²