Presentation on theme: "6-1 Solving systems by graphing"— Presentation transcript:
1 6-1 Solving systems by graphing Objective: solve systems of linear equations by graphing.Miss battaglia – algebra 1 cp
2 Warm upFind roads that intersect once, more than once, and never intersect. Describe the roads as intersecting lines, curves, or parallel lines.
3 Think & discussHow can you show all the solutions of the linear equation y = 2x – 3?Two or more linear equations together form a system of linear equations. One way to solve a system of linear equations is by graphing. Any point common to all the lines is a solution of the system.
4 Solve the system of linear equations by graphing y = 2x – 3 y = x – 1Check your answer!
5 Solve the system of linear equations by graphing y = x + 5 y = -4xCheck your answer!
6 Solving special types of systems A system of linear equations has no solution when the graphs of the equations are parallel. There are no points of intersection, so there is no solution. A system of linear equations has infinitely many solutions when the graphs of the equations are the same line. All points on the line are solutions of the system
7 Solve by graphing4y = 4 + x 1 4 x + y = -1 y axis x axis
11 entertainmentA cable company offers a “pay-per-view” club. Let c = the annual cost and n = the number of movies you watch in a year. Write a system of linear equations to decide whether to join the club.