E) what would be the total cost of purchasing the number of shirts needed to use your coupon-after your coupon is applied and a 7.5% sales tax is charged on the purchase?

a = your total price before the coupon and sales tax.

b = your coupon's given discount (for example, 25% off)

c = your discounted total

(a - (ab)) = c

c + (.075c) = your answer.

With some numbers plugged in:

a = 50$, b = - 25%

50 - (50 x. 25)

50 - 12.5 = 37.50$

37.5 + (37.5 x. 075)

37.5 + 2.82 * = 40.32$

So you would have to pay $40.32