1) The total cost is the cost of the appointment plus the cost of the repair work. The appointment costs $50. The repair work costs $120 per 2 hours. So the total cost is:
C = 50 + (120/2) t
C = 50 + 60t
For 5 hours of work, the cost is:
C = 50 + 60(5)
C = 350
It costs $350.
2) The temperature starts at 70°. It drops 10° in 4 hours. So the temperature after t hours is:
T = 70 + (-10/4) t
T = 70 − 2.5t
After 6 hours:
T = 70 − 2.5(6)
T = 55
The temperature is 55°.
3) Jennie's total pay is her weekly pay plus her commissions. If her commission is x% of her sales, then her pay is:
