A truck can be rented from company A for $110 a day plus $0.40 per mile. Company B charges $80 a day plus $0.70 per mile to rent the same truck. Find the number of miles in a day at which the rental costs for company A and B are the same.
Let m be the number of miles traveled so both rental costs for A and B are the same.
We form an equation:
110+0.4x=80+0.7x
30=0.3x
x=100 miles.