# Getting the Total value from the Nett

I can't figure out this formula; I need some help to write it out for a php script.

I have a value of $\$80$.$\$80$ is the profit from a total sale of $\$100$;$ 20\%$is the percentage margin for the respective product. Now I just have the$\$80$ and want to get the total figure of $\$100$. How can I get the total figure and what would be the formula? Your help is much appreciated. Thanks in advance. - ## 1 Answer If you mean that you get$80$from$100$after a$20$per cent discount and want to reverse the process, multiply by$\frac{100}{100-20}=\frac{5}{4}$. The formula you need is$y=\frac{5x}{4}$, so if$x=80$, then$y=100\$.

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Awesome, you just solved and made my day, thank you so much. It worked perfectly. –  sammry Nov 20 '12 at 22:13