Answer:
Nonrefundable deposit: y = 30x + 150
Refundable deposit: y = 30x
In both cases, the slope is 30.
Explanation:
The equation is:
y = 30x + 150
[Total Cost is equal to the rate per hour times the number of hours, plus the $150 deposit]
The slope is 30 [30x]
It doesn't say if the deposit will be refunded. If it is, then the total cost is: y = 30x.