a student spent 583.15 on textbook purchases. If the tax rate is 7%, what was the price of the textbooks before tax?

Question

a student spent 583.15 on textbook purchases. If the tax rate is 7%, what was the price of the textbooks before tax?

Answer 1

The answer is $545.  You simply get this answer by taking $583.15 and dividing it by 1.07.

Answer 2

In order to find the amount before tax, let's set up as if we knew what the original amount was. As a side note before we begin: a 7% tax can be written mathematically as us paying 107% the original amount. 107%=1.07 in decimals. So our formula is: (price of textbooks before tax)*(1.07)=583.15 dividing both sides by 1.07 we get (price of textbooks before tax)=$545. We can confirm our solution by multiplying $545 by a 7% tax: $545(1.07)=$583.15. This confirms our solution of $545.