# How to test a formula online?

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.

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If you have to do this rather frequently then I would recommend learning a simple programming language. For example, your problem here can probably be solved in a few lines of code in Python. As it stands, even Excel can help with this formula. –  EuYu Oct 1 '12 at 23:42
I concur strongly with the spreadsheet idea. They are easy to debug because you can see intermediate values easily. They come with graphing tools. If you need the calculation at many evenly spaced values of one variable, you can use copy down and fill series to ease the typing load. –  Ross Millikan Oct 1 '12 at 23:59
I would also recommend downloading a free CAS (en.wikipedia.org/wiki/Comparison_of_computer_algebra_systems), like SAGE or Maxima. A CAS will also force you to learn some basic programming - although your example is really easy). Additionally, you could use WolframAlpha (wolframalpha.com). Enjoy! ~A –  Amzoti Oct 2 '12 at 0:42

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.

    // My First Groovy Program
def (double X)=[0.0]

def (double H)=[2.0]
def (double O)=[23.0]
def (double D)=[0.0]
def (double E)=[0.0]

X=((H+O)/25)+(D/12970)+(E/363)+110

printf("X=%f"    ,[X])
printf(" H=%f"   ,[H])
​printf(" O=%f"   ,[O])
printf(" D=%f"   ,[D])
printf(" E=%f"   ,[E])

​

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