Question

suppose a 9 minute overseas call costs $6.48 and a 19 minute call costs $13.68. What is the cost, c, of a call of m minutes duration? write a equation to model the cost.

Answer 1

9m = 6.48

Divide both sides by 9:

m = 0.72

19m = 13.68

Divide both sides by 19:

m = 0.72

So a one minute call costs 72 cents. We can now set up an equation like this:

c = 0.72m