x的平方-1分之3x÷(1-x+1分之1)

问题描述:

x的平方-1分之3x÷(1-x+1分之1)

原式=3x/(x+1)(x-1)÷(x+1-1)/(x+1)
=3x/(x+1)(x-1)×(x+1)/x
=3/(x-1)