If Plan A costs $50 a month plus $.20 for each message and plan B costs $20 a month plus $.50 how many text messages would make plan A the better choice?

Question

 What would make plan A in this question a better choice 

Answer 1

We can write equations to represent the cost for each plan.

 

Plan A

 

y = 0.20x + 50

 

 

Plan B

 

y = 0.50x + 20

 

 

Now to find out how many text messages will make Plan A the better choice, we set an inequality.

 

Plan A < plan B

 

 

We want Plan A to be have the lowers cost.

 

 

0.20x + 50 < 0.50x + 20

 

 

Solve for x.

 

 

Subtract 20 on both sides of the inequality.

 

0.20x + 30 < 0.50x

 

 

Subtract 0.20x on both sides of inequality.

 

30 < 0.30x

 

 

Divide both sides of the inequality by 0.30

 

 

100 < x

 

x > 100

 

 

101 or more text messages will make Plan A the better choice.