Question

分式约分和通分（1）,（2）,是约分（3）,（4）是通分通分要写出最简公分母,

Answer 1

1:原式=a(a-b)/(a+b)(a-b)=a/(a+b)

2:原式=(3a+2b)(3a-2b)/(3a-2b)^2=(3a+2b)/(3a-2b)

3:左式=5/(x+1)(x-1),右式=x/(x-1)^2,两式通分

左式=5(x-1)/(x^3-x^2-x+1),右式=(x^2+x)/(x^3-x^2-x+1)

4:通分左式=2xy(x-y)/(x+y)^2(x-y)=(2x^2y-2xy^2)/(x^3+x^2y-xy^2-y^3)

右式=x(x+y)/(x+y)(x^2-y^2)=(x^2+xy)/(x^3+x^2y-xy^2-y^3)