ANSWER:
The total cost of the skate board is $74.61.
SOLUTION:
Given, Luis wants to buy a skateboard that usually sells for $79.99. all merchandise is discounted by 12%. luis has to pay a state sales tax of 6.75%.
We need to find what is the total cost of the skateboard.
Final cost is nothing but original amount subtracted by discount and added with tax.
final cost = original cost – discount + sales tax
Original cost = $79.99
Discount = 12% of original cost

discount is $9.6 approximately
Sales tax = 6% of cost after discounting

Sales tax is $4.22 approximately
Now, final cost = 79.99 – 9.6 + 4.22
= 84.21 - 9.6
= 74.61
Hence, the total cost of the skate board is $74.61