化简 (3x/x-1 -x/x+1)÷x/x²-1

问题描述:

化简 (3x/x-1 -x/x+1)÷x/x²-1

=【3x(x+1)-x(x-1)]/(x+1)(x-1) ×(x+1)(x-1)/x
=(3x²+3x-x²+x)/x
=4