Question 6441

5x^2 - 30x + 40 = 0
5(x^2 - 6x + 8) = 0
x^2 - 6x + 8 = 0
x^2 - 4x - 2x + 8 = 0
x(x - 4) - 2(x - 4) = 0
(x - 4)(x - 2) = 0 
x = 2 , x = 4 (answer)