We can solve problems where there is a percent increase or decrease by using what we know about equations. For example, a camping store increases the price of a tent by 25%. A customer then uses a \$10 coupon for the tent and pays \$152.50. We can draw a diagram that shows first the 25% increase and then the \$10 coupon.
The price after the 25% increase is $p+.25p$ or $1.25p$. An equation that represents the situation could be $1.25p-10=152.50$. To find the original price before the increase and discount, we can add 10 to each side and divide each side by 1.25, resulting in $p=130$. The original price of the tent was $130.