kak tolong dong no 5 aja (mtk kelas 10)

a = AB = B - A
= (2,-1,-3)

b = AC = C -A
= (1,-1,0)

2b - 3a
= 2(1,-1,0) - 3(2,-1,-3)
= (2,-2,0) - (6,-3,-9)
= (-4,1,9)