Aportable music player is on sale for 20% off its original price. the sale price is $96.
what was the original price of the music player?

We know that the sale price is $96 which is 80% (because 100% - 20% = 80%) of x, so we can write it down as:

96 = 80% from x
96 = 80/100 * x
96 = 8/10x
96 = 4/5x                      / * 5 (both sides)
480 = 4x                        / ÷ 4 (both sides)
x = 120

Doublecheck:

120 * 80% =
= 120 * 80/100 =
= 120 * 4/5 =
= 480/5 =
= 96

So it's correct ;)

The original price was $120.