Question

计算：(x/x-1减去x/x+1)除以2x/1-x 计算：（x-2/x+2加上x/x^2-4）除以1/x^2-4

Answer 1

1、[x(x+1)-x(x-1)]/(x+1)(x-1)×(1-x)/2x

=2x/(x+1)(x-1)×[-(x-1)/2x]

=-1/(x+1)

2、=[(x-2)²+x]/(x+2)(x-2)×(x+2)(x-2)

=x²-3x+4