200
It is:
Polynomial f(x) divided by x - n =
f(x) = (x - n)·q(x) + r(x)
The remainder r(x) is always a constant, so therefore...
f(x) = (x - n)·q(x) + r
When you set x to n...
f(n) = (n - n)·q(n) + r
Then simplify...
f(n) = (0)·q(n) + r
What is the proof of the Remainder Theorem.