Jawabanmu

2014-06-03T08:03:29+07:00
x³ + 2x² - x + 2
x1 + x2 + x3 = -2
x1x2 + x1x3 + x2x3 = -1
x1x2x3 = -2
x1^3 + x2^3 + x3^3 
= (x1 + x2 + x3)((x1 + x2 + x3)^2 - 3(x1x2 + x1x3 + x2x3)) + 3(x1x2x3)
= (-2)((-2)² - 3(-1)) + 3(-2)
= -2(7) + (-6)
= -14 - 6
= -20