Question

An education association wants to rent a cotton candy machine for a carnival. There is a deposit to rent it plus an additional $8 per hour. The total cost to rent the machine for 5 hours is $115. Assume the relationship is linear. Find and interpret the rate of change and initial value.

Answer 1

• rate of change: $8 per hour; the per-hour rental charge
• initial value: $75; the deposit on the machine

Explanation:

The cost to rent the machine is given as ...

total cost = deposit + ($8 /hour)×(number of hours)

The cost for 5 hours is given ans $115, so we have ...

115 = deposit + 8(5)

75 = deposit . . . . . . . . subtract 40

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The "rate of change" is given as $8 per hour, the hourly rental charge.

The "initial value" is called the deposit. It is found to be $75.