1、
(x^2-2x)/(x^2-1)÷[(x-1)-(2x-1)/(x+1)]
=(x^2-2x)/(x^2-1)÷[(x^2-1-2x+1)/(x+1)]
=(x^2-2x)/(x^2-1)÷[(x^2-2x)/(x+1)]
=x(x-2)/(x-1)(x+1)÷[x(x-2)/(x+1)]
=x(x-2)/(x-1)(x+1)*[(x+1)/x(x-2)]
=1/(x-1)
1/(x-1)=1/(1/2-1)=1/(-1/2)=-2
2、
根据题意得到:
x/(x-1)=3/(x^2-1)+1
x(x+1)=3+(x^2-1)
x^2+x=x^2+2
x=2
当x=2时,A=B.