Magnitude of scalar multiple

Question

Find the magnitude of the scalar multiple, where u = <2,0>

and v = <-3,6>

.

-5 v

Wouldn't the answer just be -15sq5??? Im confused on this problem

Answer 1

-5v = <15, -30>

So, ll v ll = √ [(15)² + (-30)²] = √ 1125 = √225√5 = 15√5