After a 80% ​reduction, you purchase a new clothes dryer on sale for ​$128. What was the original price of the clothes dryer​?

Question

After a 80% ​reduction, you purchase a new clothes dryer on sale for ​$128. What was the original price of the clothes dryer​?

Answer 1

Because this is an algebra problem, you should expect to be required to write a equation which expresses this information. Sometimes it's a good idea to start with something you know and understand. For example, if you have 80% off a $100 dryer, you may already know you are only paying $20. How? Write that out first:

$100 dryer that is 80% off costs $20.

$100 dryer that I pay 20% for costs $20.

$100 * 0.2 = $20

Now imagine that you want to use this same equation for your problem. Where would you plug in the numbers? How about:

$Unknown dryer that is 80% off costs $128

$x dryer that I pay 20% for costs $128

x * 0.2 = 128

Isolate x by dividing both sides of the equation by 0.2

x = $640