Answer:
632
Explanation:
So we can define decreasing x% in two ways: we can define 20% off as 80% of the original value, or we can define subtracting 20% from the original value, and both representations are useful.
In this case it's more useful to define 20% as subtracting 20%, from the original value. The reason for this, is because since we're subtracting 20% of the original value, we then know that 126.40 is 20% the original value.
So to find x% of some value, you generally use the following equation:
where A=original amount, and x is the percent. This equation is simply converting the x% to a decimal value. Since 126.40 is 20%, we can derive the following equation.
![0.20A = 126.40](https://img.qammunity.org/2023/formulas/mathematics/high-school/ybgjo02bw1sjgj5kbf31aqed2h1ttmwhfn.png)
We can solve for A, by dividing by 0.20
![A=632\\](https://img.qammunity.org/2023/formulas/mathematics/high-school/zss88cg8v4shtjltwkq4a2ir58az9qjp3i.png)
It's also important to note, you didn't really have to set up this entire equation, since you know that the 126.40 is 20%, you simply could've multiplied by 5, since 20% is really just 1/5 of the entire value, so get the entire value, or original value you multiply by 5