Algebra 1 · Systems of Equations & Inequalities
Substitution Method
Algebra 1 · Systems of Equations & Inequalities
Definition
The substitution method solves a system by replacing one variable with an equivalent expression from the other equation.
Examples
- From y = x + 1, substitute into 2x + y = 7.
- Solve one equation for a variable, then plug it in.
Key rule
Substitute to reduce the system to one equation in one variable.
Memory hook
Substitute one variable, then solve what is left.