Download CHAPTER 7: Graphing Linear Equations Section 7.2: Graphing Linear Equalities Topics: A.

MATH 0960
7.2 Notes
CHAPTER 7: Graphing Linear Equations
Section 7.2: Graphing Linear Equalities
Topics:
A. Find missing coordinates of ordered pairs.
B. Graph horizontal and vertical lines.
C. Graph linear equations by plotting points.
D. Graph linear equations using the x- and y-intercepts.
E. Solve applications.
A. Find missing coordinates of ordered pairs.
 What does a problem look like?
Find the missing coordinate if the ordered pair is to be a solution to the
equation:
(
)

Answer: ( )
What am I supposed to do?
Substitute the known coordinate into the equation and solve for the other.
B. Graph horizontal and vertical lines.
Horizontal lines:
 What does a problem look like?
Graph.

What am I supposed to do?
o Since the equation is in the form
, find the location of
o Plot the point ( ) and plot another point with
.
o Connect the points with a horizontal line.
on the -axis.
Vertical lines:
 What does a problem look like?
Graph.
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MATH 0960

7.2 Notes
What am I supposed to do?
o Since the equation is in the form
, find the location of
(
)
o Plot the point
and plot another point with
.
o Connect the points with a vertical line.
on the -axis.
C. Graph linear equations by plotting points.
 What does a problem look like?
Examples: Graph each linear equation.
1.
2.

What am I supposed to do?
Follow the steps below.
1. Solve for y: Write the equation in
form.
2. Substitute a number in for x: Evaluate to find the corresponding value for y.
).
Record the ordered pair (
3. Repeat step 2: Select two different values for x. Find a total of three ordered
pairs.
4. Plot the points: They should be collinear. Remember to label the axes with x,
y, and their respective scales.
5. Draw the line: Connect the dots to form a line and draw an arrowhead on
each end of the line.
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MATH 0960
7.2 Notes
D. Graph linear equations using the - and -intercepts.
 What does a problem look like?
Graph
.

What am I supposed to do?
When the equation is in the form
, you can often avoid writing the
equation in
form.
1. Set
so you can find and plot the intercept.
2. Set
so you can find and plot the intercept.
3. Draw the line connecting the points.
E. Solve applications.
 What does a problem look like?
Each month a gas company charges a flat rate of $5 for infrastructure
maintenance plus a fee of $10 per thousand cubic feet of gas. Let
gas usage
in thousand cubic feet, and
monthly bill. Find the equation for monthly cost
and graph the equation.
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