Solving systems of linear equations by graphing

Intros
Lessons
  1. How to find the number of solutions to systems of linear equations?
  2. How to solve systems of linear equations by graphing?
Examples
Lessons
  1. Graph the following linear equations and find the point of intersection. State the consistency.
    1. 2x - y = - 9
      x + 3y = 6
    2. 2x + 2y = 8
      3x - y = 0
    3. 4x + 6y = 12
      2x + 3y = 9
    4. y - x = 2
      4y - 8 = 4x