MPM 10: Academic Mathematics Pasquale's cell phone plan charges him monthly using the relation y = 0.25x+20, where y is the
total monthly bill and x is the number of minutes he used for the month.
(a) Which variable is independent and which is dependent?
(b) How do you know the relation is linear?
Determine the rate of change in his monthly bill.
(d) What does the rate of change mean?
How does the rate of change relate to the equation?
When will his cell phone bill reach $1000?
(1)