Ahotel manager found that his gross recipients for the day, including a 7% sales tax, totaled to $3479.64. find the amount of sales tax collected.
(i ask for someone to , quickly, me answer he question, i can't seem to properly do it myself.)

  $227.64

Step-by-step explanation:

The relevant relations are ...

  sales + tax = total

  tax = 7% × sales

Using the second equation, we can write sales in terms of the tax as ...

  sales = tax/0.07

Substituting this into the first equation gives ...

  tax/.07 + tax = total . . . . . substitute for sales

  tax(1/0.07 + 1) = total . . . . factor out tax

  tax ((1 +.07)/.07) = total . . . simplify to a single fraction

Multiply by the inverse of this fraction:

  tax = .07/1.07 × total = (7/107)($3479.64)

  tax = $227.64

a_n = a_1 + (n - 1)d

the first term is 6.

the common difference d = ?

when you find d, replace n with 7 and d with the common difference to find your answer.