a phone company offers two monthly plans. plan a costs $11 plus an additional $0.17
for each minute of calls. plan b costs $16 plus an additional $0.13 for each minute of calls.
for what amount of calling in minutes do the two cost the same?
what is the cost when the two plans cost the same?

125 minutes of calling

It will cost $32.25 when the plans cost the same.

Step-by-step explanation:

The first plan's expression would be:

11+.17x       x being the number of minutes

The second plan's expression would be:

16+.13x

You must set the expressions equal to one another. So:

11+.17x=16+.13x

Then solve for x:

.17x=5+.13x

.04x=5

x=125

So the plans will cost the same after 125 minutes. To find the cost of the plans at that time, substitute 125 in for the x in one of the equations.

11+.17(125)=y        y being the overall cost of the plan

11+21.25=y

32.25=y

To check your answer, you can substitute again in the other equation:

16+.13(125)=y

16+16.25=7

32.25=7