This video provides a good example of graphing systems of inequalities.  Pay attention to the dotted or solid lines.  The solution is where both inequalities overlap.

This video sets up a system of inequalities given a word problem.  The video solves the inequality then graphs it.  The solution to the inequality is where there is overlap in the shading.

This video solves a system of equations using substitution.  The video checks the solution using graphing.  Great video!

This is a consistent and independent system of equations that is solved using substitution.

This video solves a system with no solution using substitution.  The system is two parallel lines, which is inconsistent.

This video provides a few great examples on how to find a common multiple in order to eliminate a variable.

This video shows how to solve a system of equations by graphing using x and y intercepts.