System of Equations 3 variables - 1: shows how to solve a system of 3 three linear equations in 3 variables using the addition (elimination) method. The same problem is solved in System of Equations 3 variables - 2 but using the substitution Method.
http://www.youtube.com/watch?v=EfH1BJ3fUKg
System of Equations 3 variables - 2: shows how to solve a system of 3 three linear equations in 3 variables using the substitution method, and also partly the addition (elimination) method to solve a system of 3 equations. Same problem is solved in video above.
http://www.youtube.com/watch?v=w-bF31Pnww8
WORD PROBLEM using a system of 3 equations with 3 variables to solve: http://www.youtube.com/watch?v=AlPzx3-aYVg