# College Algebra?

The tax on food in Taco City is 3%.

a) If your after-tax total paid for food was $123.60, how much did the food cost before tax?

b) If the food costs $95.30 before-tax, how much will you need to pay in total?

Not sure where to start exactly, please show and explain, thank you!

### 2 Answers

- msoexpertLv 61 month ago
● Dollar tax amount = dollar cost or sale x tax rate

● Total bill = dollar cost before tax + dollar tax amount

So to figure out part (b), you'd first calculate the dollar amount of tax. And then add this amount to the cost before taxes. A two-step process.

But there is a fast way to get your answer in just one step. Because the total amount after tax 𝐢𝐧𝐜𝐥𝐮𝐝𝐞𝐬 the dollar amount before taxes, you're actually taking 100% of the original amount and then adding the percent tax to it. So, in your case, you'd be taking 103% of the before-tax amount.

If you do the math correctly, you will get the same answer! So you have a double-check to making sure you did the math correctly.

Now with being given the after-tax dollar amount, you're going in reverse. So instead of adding the tax, you'd be subtracting it out. So you'd do the exact opposite of the fast way mentioned above because you're going in reverse order! In other words, you'll divide the after-tax amount by 103%.

Source(s): I've taught math and business, plus many other subjects. And have helped out lots of students to help them better understand and learn. - Anonymous1 month ago
a) Divide 123.60 by 1.03 which means food cost 120 before tax.

b) divide 95.30 by 100 and multiply by rate (3%) and add to original to make the total

(if you multiply by 1.03 you do it in one step with less risk of error = 98.16)

This is the reverse of what we did in (a).