1.分式2/x^2-3x与4x/x^2-9的最简公分母是（）2.将分式-1/(x-1)(x+1),2/(x+1)(x+2),3/-(x+2)(x-1)通分后得
问题描述：
1.分式2/x^2-3x与4x/x^2-9的最简公分母是（）
2.将分式-1/(x-1)(x+1),2/(x+1)(x+2),3/-(x+2)(x-1)通分后得
答
1.2/x^2-3x=(2-3x^3)/x^2
4x/x^2-9=(4x-9x^2)/x^2
最简公分母是x^2
2.公分母是(x-1)(x+1)(x+2)
所以每项通分后得
-1/(x-1)(x+1)=1(x+2)/(x-1)(x+1)(x+2)
2/(x+1)(x+2)=2(x-1)/(x-1)(x+1)(x+2)
3/-(x+2)(x-1)=-3(x+1)/(x-1)(x+1)(x+2)
答
1.
x^3-9x
2.
(-x-2)/(x^3+2x^2-x-2)
(2x-2)/(x^3+2x^2-x-2)
(-3x-3)/(x^3+2x^2-x-2)
答
1.分式2/x^2-3x与4x/x^2-9的最简公分母是（x(x+3)(x-3)）；2.-1/(x-1)(x+1),2/(x+1)(x+2),3/-(x+2)(x-1)通分后得分别为-1(x+2)/(x-1)(x+1)(x+2),2(x-1)/(x-1)(x+1)(x+2),-3(x+1)/(x-1)(x+1)(x+2).如果要计算结果,把...