Graphing linear equations By Robert O. Mills Jr. Hermitage High School Henrico County Public Schools

Part Three Graphing

After you have discovered a relation of at least 3 ordered pairs you may now graph the linear equation.

Given the solution : y=x+4

Create a t-table with the domain (x values) as {-1, 0, 1}. y x -1 3 0 4 1 5

Place the points on a graph. x y -1 3 0 4 1 5

Add additional points to the graph.

Draw a line connecting all the points.

New solution: y=4 -x Plot table and graph points. x y -1 5 0 4 1 3

Add additional points to the graph.

Draw a line connecting all the points.

New solution: y=x-4 Plot table and graph points. x y -1 -5 0 -4 1 -3

Add additional points to the graph.

Draw a line connecting all the points.

New solution: Plot table and graph points. x y -1 2. 5 0 2 1 1. 5

Add additional points to the graph.

Draw a line connecting all the points.

New solution: Plot table and graph points. x y -1 -3 0 -2 1 -2

Add additional points to the graph.

Draw a line connecting all the points.

Please note the following: • All linear equations graph to a line. • When +x is in the final solution the line increases in value (goes up). • When -x is in the final solution the line decreases in value (goes down). • The value of y when the value of x=0 is the point where the line crosses the y axis. (y intercept)