First, you try to make sure that both the denominators are the same. In order to do this, you multiply both fractions' numerator and denominator by the other fraction's denominator. Next, you combine like terms in the numerator, and then you simplify the fraction.
Answer:
b140
Step-by-step explanation:
14*10=140 that's all
This is simple division:

So, plug it into your calculator and you get:

Your answer's that
it takes 4.5 hrs for the surveillance run.