题目

1.当x=_____时,分式|x|-2/x-2无意义.2.化简：2a/a-b+a+b/b-a=_____
化简：1.x/x²-1(x-1/（x）-2)
解方程：1.2/x-1=4/x²-1
先化简,再求值：x/(x-y)²×x²-y²/（x+y）+2x+2/（x-y）-2其中x,y满足方程组x+2y=3,x-y=2

提问时间：2021-02-22

答案

1、x=2
2、1
3、原式=x/(x+1)(x-1)×(x-1)/(x-2)
=x/(x+1)(x-2)
=x/(x²-x-2)
4、两边乘以(x+1)(x-1)得
2x+2=4
x=1
检验：x=1是增根
∴方程无解
5、原式=x/(x-y)²×(x+y)(x-y)/(x+y)+2x+2/(x-y)-2
=x/(x-y)+(2x+2)/(x-y)-2(x-y)/(x-y)
=(x+2x+2-2x+2y)/(x-y)
=(x+2y+2)/(x-y)
∵x+2y=3 x-y=2
∴原式=(3+2)/2=5/2