How many additional minutes (a) will it take for the plans to cost the same

Question

Tim is choosing between two cell phone plans that offer the same amount of free minutes. Cingular's plan charges $39.99 per month with additional at 0.45$ and Verizon's plan cost $44.99 a month with additional minutes at $0.40?

Answer 1

m represents number of minutes

 

39.99 + 0.45m = 44.99 + 0.40m         subtract 0.40 m from both sides

39.99 + 0.05m = 44.99                        subtract 39.99 from both sides

0.05m = 5.00                                       divide both sides by 0.05

m = 100

 

The cost is equal at 100 minutes.

Answer 2

Let it take x additional munites.

39.99+0.45x=44.99+0.4x

0.05x=5

x=100

so 100 minutes.