Diketahui vektor u = 2i + 3j – 2k dan vektor v = a.i – 2.j +4k. jika u. v = -4 hasil u+v

U . v = ( 2 , 3 , -2 ) ( a , -2 , 4 ) = 2a – 6 – 8 = 2a – 14
2a – 14 = – 4
2a = 14 – 4
a = 5

u = 2i + 3j – 2k
v = 5i – 2j + 4k

u + v = ( 2i + 3j – 2k ) + ( 5i – 2j + 4k ) = 7i + j + 2k