化简a²-b²/a²+ab

问题描述:

化简a²-b²/a²+ab

=[(a+b)(a-b)]/[a(a+b)]
=(a-b)/(a)
这个是正解

40/2=20 20*20*3.14*60*0.85=~

=[(a+b)(a-b)]/[a(a+b)]
=(a-b)/(a)