Equations is an equations editor with over 700 symbols and LaTeX/Visual editing

Solve Quadratic Equations using Factorisation solves a Quadratic Equation

Free

Solves boundary-value problems involving ordinary differential equations

Numerically solves systems of simultaneous nonlinear equations.

Just a little bit of hack: a linear equations solver using eval and built-in

This java applet solves linear equations of two unknown variables.

Free

Great interactive Chemistry teaching software for home and school.

A simple and free tools that will help you solve your math equations.