Answer:
20.99+ 10.29n s 100
Explanation:
Well your variable is the number of pants she wants to buy, so on top of the shirt she bought it would 20.99 + 10.29n, but you wouldn't put 100$ at the end of the sentence because for all you know she could have gone past 100 dollars. Hope this helps! Also, if we are counting this from 100 it is better to just subtract 20.99 from 100 and divide by 10.29.