Hi everyone, There's the solution, but I don't quite understand how to get to the answer? If someone could break it down to me in simplest form, that'd be much appreciative! Same situation with example 2. Thank you!!

Discount, Tax and Tip Example 1: With a 20% discount, Ella was able to save $40 on a dress. What was the original price of the dress? Solution: 20% of 20 _ _ 100 x 40 x=40,T>