Non-Runescape script help.

How do I show graphs on SCAR?
I am still trying to figure out how to basically use variables and what-not.
My basic plan was to make a script for algebra 2.Have a form come up,where they can just type in the equation like 2x + 5y = 69800.Underneath that would be something that shows the other forms of the equation and the graph for it.
Planning on it looking something like thing on bottom but I need help with how to code,basically how do I make it do simple addition and stuff using the input of the user?

Should look something like this:

Equation:[Place where user types the equation.][Submit or Enter button]

Standard form:
[A space here where the standard form of equation should go.]

Slope-Intercept:
[Space for slope-intercept for here after enter is pressed.]

Graph:
Here is where the graph would go,just a huge box like the one you get when you run the parabola thing.I don't want anyone to make it but I just need help on how to make SCAR take the information given by user,and use it to make it to 2 other equations and a graph.Thank you for looking at it,and hope you can help me.

 

Someone?