Question

Find the equivalent expression to the complex number (1/5)⋅(5i).
a.1
b.-1
c.i
d.-1

Answer 1

Multiplication is commutative. So the order in which you multiply doesn't matter. Also 5i is the same as 5 times i.

So multiply the first two factors, 1/5*5. You get 1 as the answer. Now multiple 1 times i. Any number times one is just the number. So 1*i= i