x= original price
% off= 20%
Sale $= $680
STEP 1:
Find discount amount
Discount Amount= % off * Original $
= 20% * x
change % to decimal (% ÷ 100)
= 0.20 * x
= 0.20x
STEP 2:
Find sale price
Sale Price= Original $ - Discount
= x - 0.20x
= 0.80x
STEP 3:
Sale= $680= 0.80x
Solve for x
$680= 0.80x
divide both sides by 0.80
$680/0.80= x
$850= x
ANSWER: The original price is $850
Hope this helps! :)