Question

How to find price before sale?

in a sale, Jen buys a laptop for 351.55
this price is 21% less than the price before the sale.

Answer 1

The regular price is $445.00.

Explanation:

Let `p` be the price of the laptop before the sale.

Then $351.55 is 21% less than `p`.

This means, if we take 21% of `p` away from `p`, we'll get $351.55.

In math:

`p-0.21p = $351.55`

`0.79p = $351.55`

Notice how this also means the sale price Jen pays ($351.55) is the remaining 79% of the retail price.

Solving for `p`:

`(cancel0.79p)/cancel0.79 = ($351.55)/0.79`

`"           "p=$445.00`

So the price before the sale is $445.00.