Question

a sofa regularly sells for $520. the sale price is $416 fine the percent decrease of the sale price from the regular price what percent is it?

Answer 1

The final price of the sofa can be calculated by subtracting a decrease to the original price like this:

final price = original price - decrease

In this case, the original price was $520 but finally, the sale price was $416, then by replacing 520 for the original price and 416 for the final price we get:

416 = 520 - decrease

The decrease can be written as the multiplication of the original price by the percent of decrease that we will call "x", then we get:

416 = 520 - 520x

From this equation we can solve for x like this:

416 + 520x = 520 - 520x + 520x

416 + 520x = 520

416 - 416 + 520x = 520 - 416

520x = 104

520x/520 = 104/520

x = 104/520

x = 0.2 (20%)

Then the percent of decrease equals 20%