I have an equation I have devised, it is:
$$\frac{H+O}{25}+\frac{D}{12970}+\frac{E}{363}+110 = X$$
The equation doesn't matter, I just posted it as an example. I need to be able to plug in values for $H$, $D$, $E$, and then receive what $X$ is. I don't have a graphing calculator, and I was wondering if anyone knew any websites or any way for me to do this?
I have to test it a couple hundred times, and I can't continually input this into my phone's calculator and record on paper my results. I have looked all over the web, but I'm not quite sure the wording that would accurately describe my issue, and therefore I have had no luck finding any information.
As have been suggested already you could use a spreadsheet for example, Google Docs is free and requires less than .5 hour to learn. You could also get into a programming language like JavaScript and do the task it would take you about 2 hours or so. Alternatively you could use this site: Groovy Console that allows you to run Groovy code and execute it for free - Here is the code for your application (I assumed the variables to be decimal type, but you could change the data type to int, float,...etc. based on your requirements).
Note: The language is case sensitive, so x is not the same as X.