Greg teaches martial arts. He charges a one time processing fee of $5.00 and the cost of classes are shown below. let x represent the number of classes and y represent the cost of the classes. Based on the information, what will it cost to take 10 classes?

Question

(x) classes 1 2 3 4
(y)cost of $15 $27 $39 $51
classes:

so I was able to figure out the cost goes up by $12 for each class.
that will give me $123 for 10 classes and then I have to add the $5 processing fee- giving me $128 as my answer.
Is this correct? Is there a different way of solving this using x and y?
Thanks for your help

Answer 1

If it's $12/class then 10 classes would cost 10*12 = $120 and that + a $5.00 processing fee would make $125 wouldn't it?

Answer 2

It isn't $12 a class but from the numbers they give, for example one class =$15, two classes =$27, three classes=$39, and four classes=$51
so the difference between each class is $12; not each class costs $12.
so to figure out 5 classes I added $12 to $51 dollars, getting$63; then I added $12 to that to get$75 dollars for 6 classes and so on until I got to 10 classes and it =$123 plus $5 fee.
Do you see how I did my work

Answer 3

OK. So it's 15 + 12*9 + 5 = 15 + 108 + 5 which is 128 as you had.

Answer 4

ok, Thank you