At best buy they have a 42'' tv sells for $1250. sales tax is 6.5%. what is the total cost of the tv including tax?

If the television is on sale for 15%, that means that the selling price before tax will be 100 - 15 = 5% of the original price.

1250 * 0.85 = $1062.5 ... this is your selling price BEFORE tax

Now, calculate your tax.

You would pay (1062.5) + (1062.5 * 0.065)

= 1062.5 + 69.06 (your tax)
= 1131.56 dollars