2x2 - 18x + 40 = 0 how do you solve this problem

2x^2 -18x + 40  = 0       divide through by 2

x^2 - 9x + 20   = 0       factor

(x - 5 ) (x - 4)  = 0       setting each factor to 0 , we get that x = 5  or x = 4  as the two solutions