Illian is at her favorite clothing store and has found a pair of pants that are on sale for 20% off the regular price. they are regularly $28. how much will be taken off the price?

There are several important information's already given in the question. Based on those given information's the answer to the question can be easily deduced.
Regular price of the pair of pants = $28
Percentage of discount on the regular price = 20%
Then
Amount of discount = (20/100) * 28 dollars
                               = 28/5 dollars
                               = 5.60 dollars
So the amount of $5.60 will be taken off the regular price. I hope the procedure is clear enough for you to understand. You can always use this method for solving similar type of problems without requiring any help from outside.

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.