Systems of equations

This course is a part of Algebra basics, a 8-course Topic series from Khan Academy.

Solving a system of equations or inequalities in two variables by elimination, substitution, and graphing.

This course contains 6 segments:

Systems of equations overview

This video series covers everything you need to know about systems of equations, through stories about trolls, kings, and cupcakes!

Systems of equations intro

Learn what "systems of equations" are, what counts as a solution to such a system, and how we can use graphs to solve them.

Elimination method for systems of equations

Learn about the elimination method, which is a way to manipulate systems of equations in order to solve them algebraically. This is actually very similar to the way we manipulate single equations in order to solve them!

Substitution method for systems of equations

Learn about the substitution method, which is another way to manipulate systems of equations in order to solve them.

Number of solutions to systems of equations

Learn about the possible number of solutions of systems of linear equations. Spoiler: There can be a single solution, zero solutions, or infinite solutions. These different cases define the distinctions between "consistent" and "inconsistent" systems, and between "dependent" and "independent" systems.

Solving any system of linear equations

Use everything you learned so far in order to solve any kind of system of equations!