The line models the cost of renting a bike. It costs $3 per hour plus a $4 deposit. Write an equation in slope-intercept form for the line where x is the number of hours a bike is rented and y is the total cost of renting a bike. How much does it cost to rent a bike for 5 hours?

y = ($3/1h) x+$4, it costs $19 to rent the bike for 5 hours.

Explanation:

An equation in slope-intercept form is y=m*x+n. In this case y would be the cost of rent, while x is the time. We need to determine m and n.

At the very beginning, x=0h (h is hours), the cost of rent is the deposit, so we know that $4=m*0h+n=n. Then we know that the cost of rent must increase by $3 with each hour, which means that the slope is m=$3/1h. Another way of getting this value would be to think on a particular case: after 1 hour, the cost of rent should be the deposit plus an hour of rent, or $7, so it should happen that $7=m*1h+$4 (where the $4 we already know is the value of n, and the numbers in italics are the values for the particular case we are looking for), from where we get that m*1h=$3, so m=$3/1h (the same result as before).

Putting all together, we have y = ($3/1h) x+$4, and for 5 hours we get y = ($3/1h) (5h) + $4