化简:1.b/(a-b)+a/(a+b)-2ab/(b²-a²)

问题描述:

化简:1.b/(a-b)+a/(a+b)-2ab/(b²-a²)
2.(2x/(x-3)+x/x+3)·x²-9/x
解方程:1.1-x/(x-2)+8/(x²-4)=0

1、b/(a-b)+a/(a+b)+2ab/(a+b)(a-b)
=[(a+b)b+a(a-b)+2ab]/(a+b)(a-b)
=(ab+b²+a²-ab+2ab)/(a+b)(a-b)
=(a+b)²/(a+b)(a-b)
=(a+b)/(a-b)
2、2x/(x-3)×(x+3)(x-3)/x+x/(x+3)×(x+3)(x-3)/x
=2x+6+x-3
=3x+3
3、两边乘以(x+2)(x-2)得
x²-4-x²-2x+8=0
∴-2x=-4
x=2
检验:x=2是增根
∴方程无解