Find the amount of the sales tax and the total cost.

Cost of item $800 tax rate8%

To find the amount of sales tax, we need to multiply the cost of the item by the tax rate expressed as a decimal:

Amount of sales tax = Cost of item * tax rate
= $800 * 0.08
= $64

The amount of sales tax is $64.

To find the total cost, we need to add the amount of sales tax to the cost of the item:

Total cost = Cost of item + Amount of sales tax
= $800 + $64
= $864

The total cost is $864.