Verified answer

Bonjour,

A = 28x - 21 = 7(4x-3)

B = -4x² + 18x = -2x(2x-9)

C = x(x-1)+3(x-1) = (x-1)(x+3)

D = 2x(x+5)+7(x+5) = (x+5)(2x+7)

E = (4x+7)²+4x+7 = (4x+7)(4x+7)+1(4x+7) = (4x+7)(4x+7+1) = (4x+7)(4x+8)

                                                                                           = 4(4x+7)(x+2)

F = 3(7x-1)²-7x+1 = 3(7x-1)(7x-1)-1(7x-1) = (7x-1)(3(7x-1)-1) = (7x-1)(21x-4)

G = (2x+3)²+(-4x-6) = (2x+3)(2x+3)-2(2x+3) = (2x+3)(2x+3-2) = (2x+3)(2x+1)