tolong bantu yaaa....

alpha = x, beta = y

x^2 + y^2 + 2xy =....
((x+y)^2-2xy) + 2xy =...
((-b/a)^2 - 2(c/a)) + 2(c/a) =...
((1/3)^2 - 2(-2/3)) + 2(-2/3) =...
1/9 + 4/3 - 4/3 = 1/9