algebra.js

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

console.log(expr.toString());

2x - 3

var eq = new Equation(expr, 4);

console.log(eq.toString());

2x - 3 = 4

var x = eq.solveFor("x");

console.log("x = " + x.toString());

x = 7/2

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