Ms. Sue, i don't know who Jessica,Sara, or jack is. that was kinda wierd.

but this is my question-
How would i set up the last problem that i asked?

You all seem to be posting from the same computer.

Here's your original problem.

Denise buys a shirt on sale for $21.08. this represents a 15% decrease in price. what was the original price of the shirt

Play around with these numbers until you get a reasonable answer -- something around $23 - $26.