First, convert the 33% to a real mathematical number. For percents, this is always done by dividing the 33% by 100%, or 33% / 100% = 0.330.
Second, find out what 33% of $2799 is. This is the amount of the sale discount. This is always found by mulitplying 0.330 by the item's cost $2799, like this:
0.330 x $2799 = $923.67.
So for this sale, you'll save $923.67 on this item.
This means, the cost of the item to you is
$2799 - $923.67 = $1875.33.
Alternatively, you can think about it this way. The item is 33% off. This means you'll pay 67.000% of the total cost (100% - 33% = 67.000%).
Now what's 67.000% of the total cost?
0.670 x $2799 = $1875.33.
Just like the result above, the sale price on the item is $1875.33.
Hope this helps you on your assignment! :)