Răspuns:
metoda factorului comun:
a) (x + 1)(2x – 1) + (x + 1)(3x + 4)=
(x+1)(2x-1+3x+4)=
(x+1)(5x+3)
b) (x - 1)(3x + 2) + (1 - 2x)(x - 1)=
(x-1)(3x+2+1-2x)=(x-1)(x+3)
c) (2x - 1)(1 – 3x) + (1 - 2x)(4x – 3)=
(2x-1)(1-3x-4x+3)=(2x-1)(4-7x)
d) (5x – 3)(4x + 1) -(6x + 3)(3 - 5x)=
(5x-3)(4x+1+6x+3)=(5x-3)(10x+4)=
2(5x-3)(5x+2)