Start by writing the decrease as a percent of the original price of the backpack.
30 %
Practice makes perfect
In order to find the percent decrease for the backpack price, we can write the decrease as a percent of the original price.
Decrease= Discount Percent* Original price
First, we can find the cost subtracted by the sale percent. We can do so by subtracting the sale price, $28, from the original price, $40.
Decrease $40- $28= $12
Finally, we can substitute $12 for the decrease and $40 for the original price of the backpack in our formula. We can also denote the decrease percent with an arbitrary variable x.
Decrease= Discount Percent* Original price
⇓
$12= x* $ 40
Now, we can solve our equation for x. Let's do it!
