f5
a. The temperature in the machine 30 seconds after it is turned on.
b. The time when the temperature inside the machine is 100 degrees Celsius.
4.3: You Charge How Much?
cost (dollars)
3,500
3,000
2,500
2,000
1,500
1,000
500
Illustrative
Mathematics
2 4 6 8 10 12 14 16 18 20 22
time (hours)
Two companies charge to rent time using their supercomputers. Their fees are given by
the equations f(t) = 500 + 100t and g(t) = 300 + 150t. The lines y = f(t) and y = g(t)
are graphed.
1. Which line represents y = f(t)? Explain how you know.
2. The lines intersect at the point (4, 900). What does this point mean in this situation?
3. Which is greater, f(10) or g(10)? What does that mean in this situation?