计算分式(a-5)乘以25-a²/a²-10a+25

问题描述:

计算分式(a-5)乘以25-a²/a²-10a+25

原式=(a-5)*[-(a+5)(a-5)/(a-5)²]
=(a-5)*[-(a+5)/(a-5)]
=-(a+5)
=-a-5