Can someone please help me with this statistics word problem?

Question

You have been saving the same amount of money every week. If you have been saving five dollars more than a number for five weeks less than that number, how much money have you saved so far?

Explain how your answer relates to the difference of two squares.

Answer 1

Let x be the unknown number then

x + 5 is the amount saved every week

x - 5 is the number of weeks

So the amount saved so far is

(x + 5)(x - 5) = x² - 5²