Tamara uses a coupon to save 20% off her purchase at the bookstore. The original cost of Tamara's purchase is d dollars. Which expressions represent the cost, in dollars, of Tamara's purchase after using the coupon? Choose all that apply.

The equation would be d - (d×0.2)

828. all there is to it!

here, if you ever need with rounding (or other forms of arithmetic/math) again, use this:

thats the rounding one, but if you just click the top left, it shows you all the calculators you may need!