After 7 a.m., the power usage on a college campus increases at a rate of 21% per hour.
t be the number of hours
the power usage increases at a rate of 21% per hour
21% = 0.21, constant rate = 0.21 . So slope = 0.21
Prior to 7 a.m., 15,040 kWh have been used.
At 7.am , power used = 15,040kWh. so our y intercept is 15,040
We use slope intercept form y=mx+b
slope m = 0.21 and b = 15040
power usage , y = 0.21 t + 15040
The university has a daily goal to keep their power usage less than or equal to 100,000 kWh
Power usage is less than or equal to 100,000
So inequality becomes 0.21t + 15,040 <= 100,000
