This expression is a perfect square trinomial. It has two answers but they don't have to be different. In this case it has to be the same - because it is a perfect square trinomial.
Answer: 20%.
Step-by-step explanation:
Given, The price of a shirt is marked down from $12.50 to $10.00.
Previous price = $12.50
New price = $10.00
Change in price = Previous price - New price
= $12.50 - $10.00
= $2.50
Now, the percent decrease of the shirt = 

Hence, the percent decrease of the shirt = 20%.
Answer:
Step-by-step explanation:
Answers: (y = 2) and (x = 1)
Steps: