Answer:
y=60+25h+0.3r
Explanation:
let y be the total charges 
given that the hour is h
and the cost for raw material is r
therefore
 1. The first hour of service call = $60
 2. For each additional hour= 25h
 3. 30% over the cost of the materials.= 30/100*r=0.3r
total charges
y=60+25h+0.3r
therefore the expression is 
y=60+25h+0.3r