Algebraic Methods - Substitution and Elimination
Learning to solve a pair of linear equations algebraically.
Core concept
For example, to solve x+y=10 and x-y=2 using elimination: adding the two equations directly eliminates y (2x=12, so x=6), then substituting back gives y=4. Both methods always give the same correct solution when applied properly; the choice between them is often a matter of which is more convenient for a specific pair of equations — substitution works well when one equation is already solved for a variable, while elimination works well when coefficients can be easily matched.
Exam highlight
Key diagram

Keywords worth remembering
Trending
Most searched
Study resources
Notes & downloads
Quick notes
• Substitution method: solve one equation for a variable, substitute into the other equation.
• Elimination method: add/subtract equations (after adjusting coefficients) to eliminate one variable.
• Example: x+y=10 and x-y=2, adding gives 2x=12, so x=6, then y=4.
• Both methods give the same correct solution; choice depends on convenience for the specific equations.