1.约分(1) (-16a²)/(20ab) (2) (2x-2y)/(x²-y²)

题目

1.约分(1) (-16a²)/(20ab) (2) (2x-2y)/(x²-y²)
2.通分:3x/x²-2x 2x+1/4-x² 3/2x²+4x
3.在3个整式x²-1 x²+2x+1 x²+x中,请你从中任意选择两个,将其中一个做为分子,另一个作为分母组成一个分式,并将这个分式进行化简,再求x=2时分式的值

答案

1.约分(1) (-16a²)/(20ab)=-4a/5b(2) (2x-2y)/(x²-y²)=2(x-y)/(x-y)(x+y)=2/(x+y)2.通分:3x/x²-2x =3x/x(x-2) =6x(x+2)/2x(x+2)(x-2)2x+1/4-x²=-(2x+1)/(x-2)(x+2) =-2x(2x+1) /2x(x+2)(x-...