Question

Persamaan kuadrat -x pangkat 2 - 2x + 7 = 0 mempunyai akar - akar p dan q . Nilai p pangkat 3q + pq pangkat 3 = .......

Answer 1

-x² - 2x + 7 = 0
a= -1, b = -2, x = 7
p+q = -b/a = 2
p q = c/a = 7/-1 = - 7

p³ q + pq³ = pq ( p² + q²) = pq{ (p+q)² - 2pq)}
p³ q + pq³ = (-7){ (2)² - 2(-7)} = -7 (4 +14) = -126