Question

计算:(a-3分之3a-a+3分之a)乘以a分之a的平方-9

Answer 1

(a-3分之3a-a+3分之a)乘以a分之a的平方-9

=[3a/(a-3)-a/(a+3)]×(a²-9)/a

=[(3a²+9a-a²+3a)/(a-3)(a+3)]×(a-3)(a+3)/a

=(2a²+12a)/a

=2a+12