x is a positive number such that x2+9x−22=0. What is the sum of all possible values of y which satisfy the equation x=y2−13y+24?
x^2 + 9x - 22 = 0
(x+11)(x-2) = 0
x = -11 or x = 2
but x is to be positive, so x = 2
then y^2 - 13y + 24 = 2
y^2 - 13y + 22 = 0
(y-11)(y-2) = 0
y = 11 or y = 2
so the sum of these y values is 11+2 = 13