Question 167761
The equation C = MX+B can be used to modle the monthly cost,C, of a cell phone plan where B is the flat monthly cost, M represent the cost in dollars per minute and X is the number of minutes used in the month. Choose a flat monthly rate and cost per minute and insert the values you have chosen for M and B into the equation. Then use this equation to find the total monthly cost C if 68 minutes are used.

You are given an equation and told to select any value of choice for M and B.
Then plug that into the given equation and simplify using 68 for X.

In other words, solve for C.

Since we are allowed to select a value for M and B, I will do just that.

The question also tells us to let X = 68.

I will select M = 35 cents.

I will select B = $20.

Then we plug and chug.

C = MX + B

C = (0.35)(68) + 20

C = 23.80 + 20

C = $43.80

The answer is C = $43.80 for the numbers I selected.

Why don't you do the same?  Select one value for M and one for B and simplify just as I did.  Then tell me what your answer you came up with. If this question is a homework question, you will soon learn that everyone in your class will have a different answer for C.

Did you follow?