约分:1)-4x²y/6xy² 2)a²+ab/a²-b²

问题描述:

约分:1)-4x²y/6xy² 2)a²+ab/a²-b²

1)-4x²y/6xy²
=-2x/3y
2)a²+ab/a²-b²
=a(a+b)/(a+b)(a-b)
=a/(a-b)