A gym charges $8.75 for each swimming class and a one-time registration fee of $12.50. A student paid a total of $56.25. How many swim classes did the student take?

He took 5 swimming classes.

Step-by-step explanation:

The problem states that the student paid a total of $56.25 for the classes and also the one-time registration fee. To find the number of classes, we should first subtract the one-time registration fee from the total.

$56.25 - $12.50 = $43.75

Now that we know he spent a total of $43.75 on the classes without the registration fee, we can divide that number by the cost of one class ($8.75) to calculate the total number of classes he took.

43.75 / 8.75 = 5

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb