Khan Academy: Algebra I: Systems of Equations: Age Word Problems

Sal begins this video by "massaging the equations slightly to prepare them for elimination." The equations won't be the only relaxed part of this lesson, which introduces the concept of multiplication to systems of equations. Viewers...

Elimination is another method for solving systems of equations, in addition to graphing and substitution. Sal's lecture is straightforward to understand, even for students who struggle with learning. By having a variety of options when...

Sal evaluates a word problem and then solves it by graphing systems of equations. This problem would be significant as a daily challenge, as a concept review, or as a homework assignment. Show this video only after the students have had...

Here is a challenging motion problem about two different length trains and how long it takes them to pass each other going in the same direction and opposite directions. At first glance, there doesnÕt seem to be enough information given...

Here are some more age word problems. The instructor uses a chart again to organize the information given. He works through the problem but ends the video with a solution that appears erroneous but is correct. The answer seems too large...

This presentation demonstrates how to solve an age word problem. It is worth the time it takes to view it.

This video demonstrates how to solve a system of linear equations by graphing and finding the point of intersection. [6:35]

This video gives two examples of how to solve systems of equations by elimination. The first example gives the system of equation to be solved and the second example is a word problem that involves setting up and solving the system of...

This video demonstrates more examples of how to solve systems of equations by elimination. The examples in this video require that one or both equations be scaled in order to eliminate a variable. [12:00]

This video demonstrates how to solve a system of linear equations by substitution. It also takes it a step further and graphs the system of equations on a coordinate grid. [6:04]