algebra.js

//
// algebraic equations 
// in javascript
// http://algebra.js.org/
//
load('http://algebra.js.org/javascripts/algebra.min.js');

var Expression = algebra.Expression;
var Equation =   algebra.Equation;
var Fraction =   algebra.Fraction; 

expr = new Expression("x");
expr = expr.subtract(3);
expr = expr.add("x");

if (expr.toString() != '2x - 3') throw '';

eq = new Equation(expr, 4);

if (eq.toString() != '2x - 3 = 4') throw '';

var x = eq.solveFor("x");
if (x.toString() != '7/2') throw '';