Jika X1 dan X2 akar² pers.kuadrat X²-3x-2=0 , maka nilai dari 1/x1 + 1/x2=

Karena x^2 - 3x - 2 = 0 bisa difaktorkan, maka:
x^2 -3x - 2 = 0
(x-1).(x-2) = 0
x = 1 atau x = 2
Maka:
1/x1 + 1/x2 = 1/1 + 1/2 = 3/2

1/x1 + 1/x2
= (x1+x2) / (x1.x2)

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

-->
3/-2
= - 3/2