a truck driver can be rented from company a for $40 per day plus $0.30 per mile. Company B charges $20 per day plus $0.70 per mile for the same truck. How many miles would you have to drive in one day in order for the cost of renting a truck from each company to be the same?
just set them equal for x miles:
40 + 0.30x = 20 + 0.70x
Now just solve for x