X^2-10x+16= 0
(x-8)(x-2)=0
x = 8 or 2
Going out on a limb here and guessing that the function is

Please correct me if this isn't the case.
Recall that

which converges for

.
It follows that

Answer:
2,535,008
two million , five hundred thirty five thousand, eight
If you plug in the x and y of choice b you would see that it does not equal 18.
6(3) + 3(-1) = 18
18 + (-3) = 15