Solving system of linear equations in two variables

This is a introduction lesson for solving system of linear equations in two variables. It combines three methods: graphing and two algebraic methods. It takes 50 min to explain the procedures and show practical examples. The Cartesian's coordinate system is provided for graphical examples. Basically showing these simple examples gives introductory overview of the topic. It is suggested to make next lesson as a practical workshop for students that might working individually or in groups.