Acd usually sells for $18.00. of the cd is 10% off, and sales tax is 8%, what is the total price of the cd, including tax?

The CD usually sells for $18.00, and of this price is 10% off, so you would want to first find out 10% of $18.00 is, and subtract that from $18.00

10% of 18.00 is 1.8, so:
$18.00 - 1.8 = $16.20

$16.20 is the price of the CD after a 10% off discount, but you still want to find out the total price with the sales tax.

To find the tax, find 8% of $16.20, and add that amount to $16.20
So: 
8% of $16.20 is $1.30
Add $16.20 + $1.30 = $17.50

Thus your final answer is $17.50, which is the total price of the CD, including tax.