Question

Algebra problem: a rental car agency charges a flat fee of $138 plus $27 per day to rent a certain car. Another agency charges a fee of $47 plus $40 per day to rent the same car. Find the number of days for which the costs are the same. Round your answer to the nearest whole number of days.

Answer 1

Let the number of days be x.

138 + 27x = 47 + 40x
40x - 27x = 138 - 47
13x = 91
x = 7

Ans: 7 days


Detailed working:
138 + 27x = 47 + 40x
138 + 27x - 27x = 47 + 40x - 27x
138 = 47 + 13x
138 - 47 = 47 + 13x - 47
91 = 13x
13x = 91
x = 91 ÷ 13
x = 7