The expression ax^2 + bx + c is divisible exactly by (x - 1), has a remainder of 2 when it is divided by (x + 1), and has a remainder of 6 when it is divided by (x - 2). Find a, b and c?

3 answers

using the remainder theorem, f(a) is the remainder when dividing by (x-a), we have

f(1) = 0
f(-1) = 2
f(2) = 6

So, now you have three equations to use:

a+b+c = 0
a-b+c = 2
4a+2b+c = 6

7/3 x^2 - x - 4/3

check it to be sure.
I didn't understand the last part