You've got 19 numbers. Their sum is 10(1+2+3+...+19) or
. Divide that by 19, to get
Sales tax = 7.5%
7.5% of 12.50 = (7.5/100) * 12.5 = 0.075* 12.5 = 0.9375
tax = 0.9
Total pay = price + tax = 12.5 + 0.9375 = 13.4375
Total pay ≈ 13.44
Hope this solves it.
Ok, first things first... No, she did not do the problem correctly. This question has everything to do with order of operations which says the parentheses are the first thing to be done, followed by exponents, multiplication, division, addition, and subtraction... PEMDAS. Now, technically, her first operation that she performed was incorrect because she did the exponent first, but this really doesn't affect the outcome, so we'll overlook it for now. Her next step was to go to the parentheses, but within the parentheses, she performed the wrong operation first... She should have multiplied 2 and 3, then added 4. Instead, she committed the fatal flaw in her math and added 4 and 2 then multiplied 3. As soon as that happened, the rest of the problem was incorrect because now she's adding and subtracting the wrong number.
The notes you made yourself on the side of the problem were exactly correct and if you followed them, you would have had the correct answer. The steps should have progressed like this...
2^3 + (4 + 2 * 3) -1 =
2^3 + (4 + 6) -1=
2^3 + 10 -1=
8 + 10 - 1=
18 - 1 = 17
Of course as you get better at solving this type of equation, you can combine steps. I wrote down each individual step so you could see more clearly what was going on. Have a good night!
