tolong ya butuh secepatnya

Vektor
AR : RB = 3 : 1
3BR = AR
r - a = 3b - 3r
r + 3r = 3b + a
4 r = 3b + a
R = (3b + a) / 4
R = 1/4 [3B - A] = 1/2 [ (6,-6,9) - (-2,2,1)
R = 1/2 [8,-8,8] = [4,-4,4]

Vektor
AR : BR = 3 : 1
3 BR= AR
3 (r -b) = r - a
3r - 3b = r - a
3r - r = 3b - a
2r = 3b - a
R = 1/2 [ 3B - A} = 1/2 [ (6,-6,9) - (-2, 2, 1)]
R = 1/2 [8, -8, 8] = (4, -4,4)

PR = r - p
PR = (4, -4, 4)- (1, -3, 2)
PR = (3, -1, 2) = 3i - j + 2k