3X+3Y/X^2-Y^2为什么等于3/X-Y

问题描述:

3X+3Y/X^2-Y^2为什么等于3/X-Y

因式分解
(X²-Y²)=(X-Y)(X+Y)
3X+3Y/X²-Y²=3(X+Y)/(X-Y)(X+Y)
=3/X-Y