You can
put this solution on YOUR website!
Did I also subtract the below equations correctly?
3a
a+4
−
(2a2−16a
a2−16)=
a3+8a2+16a
a3+4a2−16a−64=
a(a+4)(a+4)
(a+4)(a+4)(a−4)=
a
a−4
Thank you
Your simplification doesn't seem to make sense.
However, your final answer is CORRECT, considering that what you have is: 
By the way, you need to present these problems better. This one should be written like this: 3a/(a + 4) - (2a^2 - 16a)/(a^2 - 16)