Đáp án:
1)5x^2(x-2y) -15x(2y-x)
=5x^2 (x-2y) +15x(x-2y)
=(x-2y)(5x^2+15x)
=(x-2y).5x(x+3)
2) x^2 -y^2 -5x - 5y
= (x^2-y^2)-(5x+5y)
=(x+y)(x-y)-5(x+y)
=(x+y)(x-y-5)
3)x^2-xy +x-y
=(x^2 + x)- (xy+y)
=x(x+1) - y(x+1)
=(x+1)(x-y)
4) 5x^2 - 6x +1
= 5x^2 - 1x - 5x +1
=( 5x^2 - 5x) - ( 1x - 1)
= 5x(x-1) - 1(x-1)
=(x-1)(5x-1)
Giải thích các bước giải: