a.b=16,vektor a=3i-4j+2k b=2i+mj-5k a+b=

a.b = 16
(3,-4,2).(2,m,-5) =16
6+-4m-10 = 16
-4m= 20
m = -5 
soal 
a+b = ....
(3,-4,2)+(2,-5,-5)= (5,-9,-3)
                       = 5i - 9j - 3k

a.b = 16
Vektor a = (3, -4, 2)
Vektor b = (2, m, -5)

(3× 2) + (-4×m) + (2×(-5)) = 16
6 + (-4m) + (-10) = 16
-4m + (-4) = 16
-4m = 16 + 4
-4m = 20
m = -5

a + b
=(3i + 2i), (-4j + (-5j)), (2k + (-5k))
= 5i-9j-3k