A store is having a sale where school supplies are 30% off their original price. A backpack is on sale for $11.20. What was the original price for the backpack?

To find the original price, you could use a variable to represent the original price in this equation;

Let p represent the original price

.70 * p=11.20

to solve this, we'd isolate the variable (p)

p=11.20 :.70

p=16

The original price was $16