X represents the hours the electrician works. The 55 represents the $55 that she charges for each hour she works. The +40 for the $40 that was the price just to come to your house. The 190 is the total cost. Now, solve that equation.
55x+40=190
55x=150
x=2.72727272...
So the answer is 2.727 hours. It can be rounded as needed or turned into a decimal, 2 8/11.
