X1^3 + X2^3=.... Dari persamaan kuadrat 3X^2 + X + 2=0

jawab
3x^ 2+ x + 2 = 0
a= 3
b = 1
c = 2

x1 + x2 = -b/a = - 1/3
x1 x2 = c/a = 2/3

x1^3 + x2^3 = (x1 + x2)^3  - 3 x1x2 (x1 + x2)
= (-1/3)^3 - 3 (2/3)(- 1/3)
= - 1/27  + 2/3
= 17/27