Ok so you know how to factor quadratics. Take the c and a values (the constant and number in front of x^2 or y in this case and multiply them) you get 40 so now you need to find factors of 40 that add up to negative 13. In this case -5 and -8. So you can rewrite the equation as (y-5) *(y-8) now set each part equal to 0 so y-5 =0 and y-8 =0. You will get y = 5 and y=8