Write a system of equations that represents the number of students who rented the two types of skates.

Question

anita invites 21 firends to the skating rink for her birthday party.  The rink rents roller skates for $3 and inline skates for $5.  The total rental bill for all 22 students is $96.

Answer 1

Let x be the number of students who rented for $3 and y the number of students who rented for $5.

x+y=22 (because there were 22 students)

3x+5y=96 (rental cost)

Multiply the first equations by -3:

-3x-3y=-66 and add to the second equation: 2y=30, y=30/2=15 so x=22-15=7.

7 students used the $3 rental and 15 used the $5 rental.