Khan Academy on a Stick
Systems of equations and inequalities
Solving a system of equations or inequalities in two variables by elimination, substitution, and graphing.

Trolls, Tolls, and Systems of Equations
A troll forces us to use algebra to figure out the makeup of his currency. We end up setting up a system of equations

Solving the Troll Riddle Visually
Solving the system of equations visually. Now we can save the prince/princess

King's Cupcakes: Solving Systems by Elimination
Using simple elimination to figure out how many cupcakes are eaten by children and adults

How many bags of potato chips do people eat?
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Using elimination to solve a system of equations

Systems with Elimination Practice
Example of solving systems of equations with elimination

Talking bird solves systems with substitution
Solving systems of equations with substitution.
A system for solving the King's problems
Whether in the real world or a cliche fantasy one, systems of equations are key to solving superimportant issues like "the makeup of change in a troll's pocket" or "how can order the right amount of potato chips for a King's party." Join us as we cover (and practice with examples and exercises) all of the major ways of solving a system: graphically, elimination, and substitution. This tutorial will also help you think about when system might have no solution or an infinite number of solutions. Very, very exciting stuff!

Solving linear systems by graphing
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Solving Linear Systems by Graphing

Solving linear systems by substitution
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Solving Linear Systems by Substitution

Solving systems of equations by elimination
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Solving Systems of Equations by Elimination

Solving systems of equations by multiplication
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Solving Systems of Equations by Multiplication

Special types of linear systems
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Special Types of Linear Systems

Old video on systems of equations
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systems of equations
Super fast systems of equations
Have no time for trolls, kings and parrots and just want to get to the essence of system. This might be a good tutorial for you. As you can see, this stuff is so important that we're covering it in several tutorials!

Solving linear systems by graphing
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Solving Linear Systems by Graphing

Testing a solution for a system of equations
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Testing a solution for a system of equations

Graphing Systems of Equations
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Graphing Systems of Equations

Graphical Systems Application Problem
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Graphical Systems Application Problem

Example 2: Graphically Solving Systems
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Solving systems by graphing 2

Example 3: Graphically Solving Systems
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Solving systems by graphing 3
Solving systems graphically
This tutorial focuses on solving systems graphically. This is covered in several other tutorials, but this one gives you more examples than you can shake a chicken at. Pause the videos and try to do them before Sal does.

Inconsistent systems of equations
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Systems of equations without a solution

Infinite solutions to systems
Consistent, but dependent systems of equations

Consistent and Inconsistent Systems
Consistent and Inconsistent Systems

Independent and Dependent Systems
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Independent and Dependent Systems
 Constructing solutions to systems of equations
Thinking about solutions to systems
You know how to solve systems of equations (for the most part). This tutorial will take things a bit deeper by exploring cases when you might have no solutions or an infinite number of them.

Example 1: Solving systems by substitution
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Solving systems by substitution 1

Example 2: Solving systems by substitution
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Solving systems by substitution 2

Example 3: Solving systems by substitution
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Solving systems by substitution 3

The Substitution Method
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The Substitution Method

Substitution Method 2
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Substitution Method 2

Substitution Method 3
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Substitution Method 3
Solving systems with substitution
This tutorial is focused on solving systems through substitution. This is covered in several other tutorials, but this one focuses on substitution with more examples than you can shake a dog at. As always, pause the video and try to solve before Sal does.

Example 1: Solving systems by elimination
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Solving systems by elimination

Example 2: Solving systems by elimination
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Solving systems by elimination 2

Addition Elimination Method 1
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Addition Elimination Method 1

Addition Elimination Method 2
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Addition Elimination Method 2

Addition Elimination Method 3
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Addition Elimination Method 3

Addition Elimination Method 4
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Addition Elimination Method 4

Example 3: Solving systems by elimination
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Solving systems by elimination 3

Systems with Elimination Practice
Example of solving systems of equations with elimination
Solving systems with elimination (additionelimination)
You can solve a system of equations with either substitution or elimination. This tutorial focuses with a ton of examples on elimination. It is covered in other tutorials, but we give you far more examples here. You'll learn best if you pause the videos and try to do the problem before Sal does.
 Using a system of equations to find the price of apples and oranges

Linear systems word problem with substitution
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Algebraic Word Problem
 Systems of equation to realize you are getting ripped off
 Thinking about multiple solutions to a system of equations

Systems and rate problems
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Systems and rate problems

Systems and rate problems 2
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Systems and rate problems 2

Systems and rate problems 3
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Systems and rate problems 3

Officer on Horseback
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Not quite a brain teaser but fun nonetheless!

Two Passing Bicycles Word Problem
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Algebra word problem involving two bicycles passing each other.

Passed Bike Word Problem
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Fun algebra word problem involving a train passing a bike.

System of equations for passing trains problem
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Trains passing at different rates.

Overtaking Word Problem
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3 people overtaking each other at different rates

Multple examples of multiple constraint problems
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Systems of equations word problems
This tutorial doesn't involve talking parrots and greedy trolls, but it takes many of the ideas you might have learned in that tutorial and applies them to word problems. These include rate problems, mixture problems, and others. If you can pause and solve the example videos before Sal does, we'd say that you have a pretty good grasp of systems. Enjoy!

Testing Solutions for a System of Inequalities
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Testing Solutions for a System of Inequalities

Visualizing the solution set for a system of inequalities
Visualizing the solution set for a system of inequalities

Graphing systems of inequalities
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Graphing systems of inequalities

Graphing systems of inequalities 2
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Graphing systems of inequalities 2

System of Inequalities Application
System of Inequalities Application

CA Algebra I: Systems of Inequalities
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3337, systems of equations and inequalities
Systems of inequalities
You feel comfortable with systems of equations, but you begin to realize that the world is not always fair. Not everything is equal! In this short tutorial, we will explore systems of inequalities. We'll graph them. We'll think about whether a point satisfies them. We'll even give you as much practice as you need. All for 3 easy installments of... just kidding, it's free (although the knowledge obtained in priceless). A good deal if we say so ourselves!

Systems of Three Variables
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Systems of Three Variables

Systems of Three Variables 2
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Systems of Three Variables 2

Solutions to Three Variable System
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Solutions to Three Variable System

Solutions to Three Variable System 2
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u14 l3 t1 we4 Solutions to Three Variable System

Three Equation Application Problem
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Three Equation Application Problem

NonLinear Systems of Equations 3
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NonLinear Systems of Equations 3
Systems with three variables
Two equations with two unknowns not challenging enough for you? How about three equations with three unknowns? Visualizing lines in 2D too easy? Well, now you're going to visualize intersecting planes in 3D, baby. (Okay, we admit that it is weird for a website to call you "baby.") Tired of linear systems? Well, we might just bring a little nonlinearity into your life, honey. (You might want to brush up on your solving quadratics before tackling the nonlinear systems.) As always, try to pause the videos and do them before Sal does!

NonLinear Systems of Equations 1
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NonLinear Systems of Equations 1

NonLinear Systems of Equations 2
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NonLinear Systems of Equations 2

NonLinear Systems of Equations 3
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NonLinear Systems of Equations 3
 Systems of nonlinear equations 2
 Systems of nonlinear equations 3
Nonlinear systems of equations
Tired of linear systems? Well, we might just bring a little nonlinearity into your life, honey. (You might want to brush up on your solving quadratics before tackling the nonlinear systems.) As always, try to pause the videos and do them before Sal does!