Question

Brianna went to Los Angeles for a vacation. She spent 5 nights at a hotel and rented a car for 6 days. Justin stayed at the same hotel, but spent 7 nights and rented a car for 8 days from the same company. If Brianna paid $1170 and Justin paid $1610, how much did one night at the hotel cost?

Answer 1

$150 per night

Use a system of equations using x (cost of hotel) and y (cost of car): 

5x + 6y = 1170 

7x + 8y = 1610 

Solve for y in one of the equations and then use substitution to solve for x in the other: 

6y = 1170 - 5x 

y = (-5/6)x + 195 

7x + 8((-5/6)x + 195) = 1610 

7x + (-20/3)x + 1560 = 1610 

(1/3)x +1560 = 1610 

(1/3)x = 50 

x = $150 a night