Question

cell phone company A charges a fee of $50 per month plus an additional $0.10 for every minute talked. cell phone company B computes its monthly charge by using the equation y=$0.05 + $75 where y is the total cost and X is the number of minutes talked.

Answer 1

We will first write A equation

Let x be the number of minutes

y = 0.10x + 50

Comparing the above with y=mx + b where m is the rate of change

m = 0.10

Company B

y = 0.05x + 75

comparing with y =mx + b

rate of change (m) = 0.05

Hence, company A has a higher rate of change at $0.10