Oceanside Bike Rental Shop charges a 16 dollar fixed feed plus 8 dollars an hour for renting a bike. Tom paid 48 dollars to rent a bike. How many hours did he pay to have the bike checked out?

Y = mx + b

y is the total cost

The slope m is the rate: that's $8 per hour

x is the number of hours

b is the initial value: that's $16

y = 8x + 16

The problem states that the cost was $48.

Substitute that for y and solve for x.

48 = 8x + 16

32 = 8x

x = 4 hours