(X+1)(x+2)
(Х-1)(х-4)
(2х-3)(5х-1)
(4х-3)(3х+1)
Хелп

(X+1)(x+2)=x²+2x+x+2=x²+3x+2(Х-1)(х-4)=x²-4x-x+4=x²-5x+4(2х-3)(5х-1)=10x²-2x-15x+3=10x²-17x+3(4х-3)(3х+1)=12x²+4x-9x-3=12x²-5x-3