1/x^2-4,1/4-2x,1/x+2通分

问题描述:

1/x^2-4,1/4-2x,1/x+2通分

1/(x^2-4)=2/[2(x-2)(x+2)] 1/(4-2x)=-(x+2)/[2(x-2)(x+2)] 1/(x+2)=2(x-2)/[2(x-2)(x+2)]