4.2 Graphing linear equations Objective: Graph a linear equation using a table of values

Linear Equations  A linear equation in x and y is an equation that can be written in the form Ax + By = C  Note: A and B are not both zero.  A solution of an equation in two variables is an ordered pair (x,y) that makes the equation true.

Check Solutions of Linear Equations  Determine whether the ordered pair is a solution of x + 2y = 5  (1,2)  (7, -3)

Practice  Determine whether the ordered pair is a solution of 2x + y = 1.  (-3,7)  (3, -7)

Function Form  A two-variable equation is written in function form if one of its variables is isolated on one side of the equation.  Example: y = 3x + 4 is in function form. 2x + 3y = 6 is NOT in function form

Find Solutions of Linear Equations  Find three ordered pairs that are solutions of -2x + y = -3

Practice  Find three ordered pairs that are solutions of 3x + y = 4

Graphs of Linear Equations  The graph of an equation in x and y is the set of all points (x,y) that are solutions of the equation.  The graph of a linear equation can be shown to be a straight line.

Graph a Linear Equation  Use a table of values to graph y = 3x – 2

Graph a Linear Equation  Use a table of values to graph y = – 2x + 1

Practice Use a table of values to graph 4y – 2x = 8

Practice Use a table of values to graph 2x – y = 7