The substitution method

The idea of the substitution method is to reduce the number of unknowns one step at a time: we take an equation, isolate one unknown and substitute it into the others.

Example — Substitution method

To solve a system we take one equation at a time and isolate one unknown: $\begin{cases} L - G = 5 \implies L = G+5 \end{cases}$ Then we substitute the expression found into the other equations, obtaining a system with one fewer unknown.

Connections

Topics: Linear systems
Concepts: Substitution method · System of equations
Methods: Systems by substitution
Skills: Solving systems