Giải thích các bước giải:
Bài 1: a/ $3x^2-6x=3x(x-2)$
b/ $2xy+2xyz=2xy(1+z)$
c/ $15x^2y-9x^2y^2=3x^2y(5-3y)$
d/ $27x^3+6x^2=3x^2(9x+2)$
e/ $2x^2(x-3)-x(x-3)=x(x-3)(2x-1)$
f/ $(3x-6y)x+y(x-2y)=3(x-2y)x+y(x-2y)=(x-2y)(3x+y)$
Bài 2:
a/ $3(x-y)-5x(y-x)$
$=3(x-y)+5x(x-y)$
$=(x-y)(3+5x)$
b/ $\dfrac{2}{5}x(y-1)+\dfrac{2}{5}y(1-y)$
$=\dfrac{2}{5}x(y-1)-\dfrac{2}{5}y(y-1)$
$=\dfrac{2}{5}(y-1)(x-y)$
c/ $x(x-1)-y(1-x)$
$=x(x-1)+y(x-1)$
$=(x-1)(x+y)$
d/ $7x(5x-y)+2(5x-y)-3y(y-5x)$
$=7x(5x-y)+2(5x-y)+3y(5x-y)$
$=(5x-y)(7x+3y+2)$
e/ $2y(3-x)+3xy(x-3)$
$=2y(3-x)-3xy(3-x)$
$=y(3-x)(2-3x)$
Chúc bạn học tốt !!!
