Question

If a=i-2j and b= 2i - xj are parallel, then x is.....
a) 4 3 2 ) 2 d 4.​

Answer 1

x = 4

Explanation:

a = i-2j

b = 2i-xj

1 = k•2

-2 = k•(-x)

=> 1/2 = k

=> (-2)/(-x) = k

=> 1/2 = (-2)/(-x) => 1/2 = 2/x => x = 4