the only items that had sales tax were $3.00 and $0.50. The total tax for the both was $0.21 so you can find what percent 0.21 is of 3.00 + 0.50 o 3.50. Do this by dividing the percent you are looking for, 0.21, by what it is the percent of 3.50. 0.21 / 3.50 = 0.06. then you multiply the number you got, in this case 0.06 by 100 to find the percentage so it is 6%
The answer for b
Here you can just take the subtotal, $13.00, and subtract all the other prices and you will be left with the price of the top. 13.00 - 3.00 - 2.00 - 0.50 = 7.50. So the answer is $7.50
the expression is 3(15+7). An word problem could be there are 15 apples and 7 bananas. Someone needs to buy 3 times the amount of those. This is represented by that expression.
