jika faktor-faktor f(x) =3x³-5x +px+q adalah (x+1) dan (x-3)maka nilai P dan Q berturut adalah

x+1 = 0
x = -1

f(-1) = 3(-1)³-5(-1)+p(-1)+q
0 = -3+5-p+q
p-q = 2

x-3 = 0
x = 3

f(3) = 3(3)³-5(3)+p(3)+ q
0. = 81-15+3p+q
3p+q = -66

p-q = 2
3p+q = 66
---------------- +
4p. = 68
p = 17
q = 15