Math
posted by David .
Let f(x) = 1/(x+7)+15/(x8). Find all a for which f(a)=f(a+15).
How do I solve this problem?
I understand this so far
f(a)=f(a+15)
1/(7+a) + 15/(a8) = 1/(a+22) + 15/(a+7)
I am lost after that
This is a multiple choice question and I am not getting any of the choices
a.) 161/8
b.) 120/7
c.) 161/7
d.) 17

I did it in my head and I didn't get any of the answers either. I recommend you do as I told, recheck once more.