We start with simple world problems that can be solved mentally. There comes a point where problems are too difficult to solve mentally and you need to use symbolic algebra.
Algebra is based on a balance scale. The rules of algebra are derived from a balance scale.
You can multiply and divide both sides of an equation so long its done on all terms to maintain balance
Examples and exercises, for 1 step, 2 step, 3 step, and 4 step problems