Verified answer

Bonjour,

A = (2x - 3) (7 - x)

A = 14x - 2x² - 21 + 3x

A = - 2x² + 14x + 3x - 21

A = - 2x² + 17x - 21

B = (x + y) (2x - y)

B = 2x² - xy + 2xy - y²

B = 2x² - y² + xy

C = (x - 7) (2 + y)

C = 2x + xy - 14 - 7y

C = 2x - 7y + xy - 14

D = (x - 1) (1 - x)

D = x - x² - 1 + x

D = - x² + x + x - 1

D = - x² + 2x - 1

E = 3 (3a + 4)²

E = 3 (9a² + 24a + 16)

E = 27a² + 72a + 48

F = - 5 (4 - b)²

F = - 5 (16 - 8b + b²)

F = - 80 + 40b - 5b²

F = - 5b² + 40b - 80.