Gary teaches Native Alaskan dance. He charges a one−time processing fee of $5.00 and the cost of the classes is shown below. Let x represent the number of classes and y represent the cost of classes. Based on this information, what will it cost to take 10 classes (including processing fee)?

Cost of classes (not including processing fee)

Number of Classes, x 1 2 3 4
Cost of Classes, y $15.00 $27.00 $39.00 $51.00

$123.00
$125.00
$128.00
$130.00

Question

Gary teaches Native Alaskan dance. He charges a one−time processing fee of $5.00 and the cost of the classes is shown below. Let x represent the number of classes and y represent the cost of classes. Based on this information, what will it cost to take 10 classes (including processing fee)?

Cost of classes (not including processing fee)


Number of Classes, x 	1 	2 	3 	4
Cost of Classes, y 	$15.00 	$27.00 	$39.00 	$51.00
 	
	$123.00
	$125.00
	$128.00
	$130.00

anonymous · Answer

plot it and see what kind of function it is

jdoe0001 · Answer

$\huge a_n= a_1+(n-1)d$
d = difference between terms
n= nth term, in this case 10
$a_1$ = 1st term

jdoe0001 · Answer

so, what's "d", or the difference between terms?

jdoe0001 · Answer

$$
\begin{matrix}
x&&y\
\hline\
1&& $15\
2&& $27\
3&& $39\
4&& $51
\end{matrix}
$$

anonymous · Answer

lol :P

anonymous · Answer

am I'm sorry but I'm really confused

anonymous · Answer

you went in reverse order it seems

jdoe0001 · Answer

from the 1st class to the second, how much more do you pay?

jdoe0001 · Answer

reverse?    hehe,  the same as typed in :)

anonymous · Answer

$13

jdoe0001 · Answer

27-15 = 13?

anonymous · Answer

yes!

anonymous · Answer

oh k nevermind you using a different formula. Much quicker but dont forget the formula Michele.

jdoe0001 · Answer

let's check google calculator, what it says https://www.google.com/search?client=opera&rls=en&q=27+-+15&sourceid=opera&ie=utf-8&oe=utf-8&channel=suggest

anonymous · Answer

oh 12 sorry is did the math in my head it was probably off.

jdoe0001 · Answer

so, how much more would you pay from the 2nd class to the 3rd class?

jdoe0001 · Answer

I mean in the 3rd class you'd be able to use the hula hoop I'd think, thus is $39

anonymous · Answer

oh so i multiply 12 by 6, because 6 the 4 = 10 , then i multiply the answer 71 by $51

anonymous · Answer

but wait in the first it says there is a 5 processing fee so actully it would be15-5 27-10 = 17

anonymous · Answer

whatever, well i think I got it now so thankyou.

anonymous · Answer

it be an+5

jdoe0001 · Answer

27 -15 = 12
39 - 27 = 12
51 - 39 = 12

so
$$
	ext{so the difference "d" between terms is} \color{red}{12}\
	ext{the term you want is the } \color{red}{10}th\
	ext{and the 1st term is }$\color{red}{15}\
\huge a_n= a_1+(n-1)d \
\implies \huge a_{\color{red}{10}}= \color{red}{15}+(\color{red}{10}-1)\color{red}{12}
$$

jdoe0001 · Answer

and as timo86m  said, don't forget the "processing fee", +5 to that

anonymous · Answer

so the answer is 123