Đáp án:
Giải thích các bước giải:
$\text{ a)5x-20y=5(x-4y)}$
$\text{b)5x(x-1)-3x(x-1)=(x-1)(5x-3x)}$
$\text{c)x(x+y)-5x-5y=x(x+y)-5(x+y)=(x+y)(x-5)}$
$\text{d)(x-y)² - (x-y) = (x-y)(x-y-1)}$
$\text{e)a²(x-y)+b²(x-y)=(x-y)(a²+b²)}$
$\text{f)2a(x-y)-(y-x)=2a(x-y)+(x-y)=(x-y)(2a+1)}$
$\text{g)x(x-4)-2x+8=x(x-4)-2(x-4)=(x-4)(x-2)}$
$\text{h)8x²+12x+4=8x²+8x+4x+4=8x(x-1)+4(x-1)=(x-1)(8x+4)=(x-1)(x+2)×4}$
$\text{i)5x²-25xy+10y²=5x²-5xy-20xy+10y²=5x(x-y)-10y(x-y)=(x-y)(5x-10)}$