Step-by-step explanation:
you multiply 19.99 * .85 because you are taking away 15% of the total cost which leaves you paying 85% of the price. therefore you multiply $19.99 * 85% which gives you $16.99 and you multiply that by the sales tax which is 6%. when you multiply 16.99 * 0.06 it gives you 1.1 you then add the total cost which is $16.99 + $1.1 which is a total of $18 and if you pay with a $20 bill your change is $2 whit 0¢
