Mohon kak jawabannya bingung

10.
A(-2,13)
B(6,1)
C(x,y)    ----> dimisalkan aja

AC/CB = 1/3
3AC = CB

AC = C-A = (x-(-2) , y-13) = (x+2 , y-13)
CB = B-C = (6-x , 1-y)

3AC = CB
3(x+2 , y-13) = (6-x , 1-y)
(3x+6 , 3y-39) = (6-x , 1-y)

diperoleh
3x+6 = 6-x
3x+x = 6-6
4x = 0
x = 0

3y-39 = 1-y
3y+y = 1+39
4y = 40
y = 10

jadi C (0,10)
jawab (A)