Answer :

Lilith
[tex]\frac{3a^3-75a}{a(a+5)(a+5)}=\frac{3a(a^2-25) }{a(a+5)(a+5)}=\frac{3a(a - 5)(a+5) }{a(a+5)(a+5)} =\frac{3 (a - 5) }{ (a+5) }[/tex]