salah satu akar persamaan x2+6x+p=0 adalah dua kali akar yang lain. Maka nilai p adalah...

x1 = 2.x2

x^2 + 6x + p = 0
x1 + x2 --> 2x2 + x2 = 3x2
= -b/a
= -6/1
3x2 = -6
x2 = -6/3
x2 = -2

x1 = 2x2
= 2(-2)
= -4

x1 . x2 = c/a
(-4)(-2) = p/1
8 = p

Nilai p = 8

x^2 + 6x + p = 0

a = 1
b = 6
c = p
misal :
x1 = 2(x2)

x1 + x2 = - b/a
2(x2) + x2 = - 6/1
3(x2) = - 6
x2 = -6/3
x2 = -2

x1 . x2 = c/a
2(x2) . x2 = p/1
2(x2)^2 = p

p = 2(x2)^2
p = 2(-2)^2
p = 2 × 4
p = 8

Jadi nilai p adalah 8