Solving Linear Systems by Graphing

Solving Linear Systems by Graphing

Grade 9th Grade · Math · 45 min

What's Included

Learning Objective

I can solve systems of linear equations by graphing.

Reading Passage

Solving Systems by Graphing

When you encounter two or more linear equations that share the same variables, you have a system of linear equations. Solving such a system means finding the specific values for those variables that satisfy every equation simultaneously. One powerful method for achieving this is by graphing each equation on the same coordinate plane.Each linear equation, when graphed, forms a straight line. The fundamental idea behind solving a system by graphing is that the point where these lines intersect represents the solution to the system. This intersection point's coordinates (x, y) are the unique values that make both equations true.To apply this method, first ensure each equation is in a graphable form, such as slope-intercept form (y = mx + b). Then, carefully plot each line on the same grid. Once both lines are drawn, visually locate their point of intersection. The x-coordinate and y-coordinate of this point constitute your potential solution.It is crucial to verify this solution by substituting the x and y values back into both original equations. If the values make both equations true, you have found the correct solution.Not all systems behave the same way. If the lines are parallel and never intersect, the system has no solution. If the two equations actually represent the exact same line, then every point on that line is a solution, meaning there are infinitely many solutions. Understanding these graphical interpretations provides a clear visual understanding of a system's behavior.

Guided Notes

3 key concepts

  • 1

    A system of linear equations consists of two or more linear equations that share the same variables, and solving it means finding values that satisfy all equations simultaneously.

  • 2

    When solving a system by graphing, the point of intersection of the lines represents the solution, where its x and y coordinates make both equations true.

  • 3

    If the lines in a system are parallel and never intersect, there is no solution; however, if the equations represent the exact same line, there are infinitely many solutions.

Practice Questions

7 questions · Multiple choice & Short answer

Exit Ticket

Quick comprehension check

Solve the following system of linear equations by graphing. Identify the coordinates of the point of intersection and verify your solution by substituting the coordinates into both original equations.y = x + 1y = -x + 3

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