Find the sales tax. Then find the total cost of the item. Sales Tax
Selling Price Rate of Sales Tax Sales Tax
$40.00
7%
?
The sales tax is $

Step-by-step explanation:

You must state the "price before tax".  Let this be P.  Also, you must state the sales tax rate.  Let this be r, where r is a decimal fraction.  

Then the sales tax is rP, the product of the tax rate and the "price before tax."

The total cost of the item (for which it is sold) is (P + rP)($40).

If P = $40 and the sales tax rate is 7%, then

this total cost is (1 + 0.07)P = 1.07P = $42.80

Your question would be clearer if you wrote it like this:  Given that the base price of an item is $40 and that the sales tax rate is 7%, find the total cost of the item with tax.  That would be (1 + 0.07)($40), or $42.80.

The sales tax is $42.80 - $40 = $2.80.

29.5977692753

step-by-step explanation:

step-by-step explanation: