1. Graphing Linear Equations

2. Chapter Sections
7.1 – The Cartesian Coordinate System and Linear Equations in Two Variables
7.2 – Graphing Linear Equations
7.3 – Slope of a Line
7.4 – Slope-Intercept and Point-Slope Forms of a Linear Equation
7.5 – Graphing Linear Inequalities
7.6 – Functions
Chapter 1 Outline

3. Graphing Linear Equations

4. Graph by Plotting Points
Solve for y: Solve the linear equation for the variable y. That is, get y by itself on the left side of the equation.
Substitute a number in for x: Select a number and substitute it into the equation for x and find the corresponding value for y. Record the ordered pair (x,y).
Repeat step 2: Select two different values of x. This will give you two additional ordered pairs.
Plot the points: Plot the three ordered pairs. The three points should be collinear. If they are not, recheck your work.
Draw the line: Draw a straight line through the points.

5. Graph by Plotting Points
Graph the equation y = 2x + 4.
Let x = -1
y = –2 + 4
y = 2
This give us the point (-1, 2).
Let x = 0
y = 0 + 4
y = 4
This give us the point 0, 4).
Let x = 1
y = 2 + 4
y = 6
This give us the point (1, 6).
Plot the points and draw the line.

6. Graph by Plotting Points
Plot the points (-1, 2), (0, 4), and (1, 6).
Draw the line.

7. Graph Using Intercepts
Find the y-intercept by setting x equal to 0 and finding the corresponding value of y.
Find the x-intercept by setting the y equal to 0 and finding the corresponding value of x.
Determine a checkpoint by selecting a nonzero value for x and finding the corresponding y.
Plot the two intercepts and the check point.
Draw a straight line through the points.

8. Graph Using Intercepts
Graph the equation 3y = 6x + 12.
Let x = 0
3y = 6(0) + 12
y = 4
This gives us the y-intercept (0, 4).
Let y = 0
-3(0) = 6x + 12
x = -2
This gives us the x-intercept (-2, 0).
y =8
Let x = 2
3y = 6(2) + 12
3y = 24
This gives us the point (2, 8)
Plot the points and draw the line.

9. Graph by Plotting Points
Plot the points (-2, 0), (0, 4), and (2, 8).
Draw the line.