A $480 TV was put on sale for 30% off.
That means after the first reduction the price was only
100%-30% or 70% of the original price.
70% of $480 = 0.70×$480 = $336
It didn't sell so the price was lowered an additional
percent off the sale price
`
What was the second percent discount that was given?
Let the additional percent be x%
That means after the second reduction the price was only
(100-x)% of the $336
making the new price $285.60.
So the equation is:
(100-x)% of $336 = $285.60


Multiply both sides by 100
(100-x)×336 = 28560
100×336-336x = 28560
33600-336x = 28560
-336x = -5040
%
Edwin