Trying to find an example to go by for simple algebra solver

Greetings

I am very new to Android development

I would like to develop a simple app th开发者_如何学Pythonat would have 3 boxes 1) V 2) I 3) R

and I will put numbers in 2 of the 3 boxes and and then pick out which box is empty and solve for that one and place the calculated value in that box.

V = IR; I = V/R; R = V/I

Is there an example I can go by?

Thanks Sparky_

Some time ago I published on my project a class to solve math formulas like this, it's for Jave SE, but I think you can copy it to Android.

https://github.com/MarkyVasconcelos/Towel/wiki/Expression

The class source can be found in https://github.com/MarkyVasconcelos/Towel/blob/master/src/com/towel/math/Expression.java