(3x+9)/(4-4x+x^2)÷（x+3）/(x-2)
问题描述：
(3x+9)/(4-4x+x^2)÷（x+3）/(x-2)
答
(3x+9)/(4-4x+x^2)÷（x+3）/(x-2)
=3(x+3)/(x-2)²×(x-2)/(x+3)
=3/(x-2)