x^2y-xy^2)/(x-y)=__xy(x-y)/(x-y)=xy____
(a^2-9)/(a+3)=__=(a+3)(a-3)/(a+3)=a-3___
(m^2+2mn+n^2)/(m+n)=__=(m+n)^2/(m+n)=m+n___
(4x^2-4x+1)/(1-2x)=(1-2x)^2/(1-2x)=1-2x
(a^2-64)/(a-8)=(a+8)(a-8)/(a-8)=a+8
(3x^3 y^2+6x^2 y^3)/(x+2y)=3x^2y^2(x+2y)/(x+2y)=3x^2y^2
(-9m^2+4n^2)/(3m+2n)=(2n+3m)(2n-3m)/(3m+2n)=2n-3m
(4a^2-20ab+25b^2)/(5b-2a)=(5b-2a)^2/(5b-2a)=5b-2a
(1-16a^4)/(4a^2+1)/(2a+1)=(1-4a^2)(1+4a^2)/[(4a^2+1)(2a+1)]=(1+2a)(1-2a)/(1+2a)=1-2a
解方程
x^2+2x=0
x(x+2)=0
x=0,x=-2
9x^2-4=0
(3x+2)(3x-2)=0
x=-2/3,x=-2/3
-1/2x^2+2x=0
-1/2x(x-4)=0
x=0,x=4
(3a-4)^2=25
(3a-4)^2-25=0
(3a-4+5)(3a-4-5)=0
(3a-1)(3a-9)=0
a=1/3,a=3