Graphing Linear Equations

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Graphing Linear Equations

• Essential Question How do you graph linear
  equations using point plotting, intercepts, the
  slope-intercept form, and the graphing calculator?

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Graphing Linear Equations Using Point Plotting
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In order to graph using point plotting, you will
need to create a table. You will need to choose
at least 3 numbers for x and plug them into
the equation to find corresponding y values.
Plot the points
For Example Graph y 2x - 1
x y
Choose x values
-1
2(-1)-1-3
0
2(0)-1 -1
1
2(1)-1 1
plug x into the equation
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Graph using point plotting
x y
(-2) 3 2
-2 0 2
(0) 3 3
(2) 3 4
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Graphing Using Intercepts
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To graph using intercepts, you will need to find
both the X and the y intercept To find the
x-intercept, substitute 0 for y and solve for
x To find the y intercept, substitute 0 for
x and solve for y For example y 4x 8
X-intercept 0 4x 8 -8 4x -2 x
Y Intercept Y 4(0) 8 Y 8
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Graph 2x 3y 6 using intercepts.
X-intercept 2x 3(0) 6 2x 6 X
3
Y-intercept 2(0) 3y 6 3y 6 Y
2
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Graphing Using the Slope-Intercept Form
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To graph a linear equation, you will need to find
the slope and the y-intercept for the equation.
Remember y mx b
slope
Y-intercept (the point where the graph
crosses the y-axis)
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Slope Y-intercept
Graph
1. Plot the y-intercept

• Use the slope to find
• the next point
• Slope rise over run

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Graph 2x 5y 10 using the slope-intercept
form (put the equation in slope-intercept form
first)
2x 5y 10 5y 10 2x y 2 2/5 x
slope -2/5 y intercept 2
A negative slope means you will go down then
right from the y-intercept
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Graphing Using the Graphing Calculator
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Use the link below to access an online graphing
calculator
http//www.coolmath.com/graphit/index.html
When using the calculator, you will first need to
have the equation in slope-intercept form (y mx
b)
Then simply key in the equation and hit EVAL to
see the graph
Graph on the graphing calculator
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Graph 3x 5y 9 on the graphing calculator.
(First you will need to solve for y).
3x 5y 9 -5y 9 3x
Put the above equation into the graphing
calculator and click EVAL
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Assignment and Review

• Use the word document link below to access a
  homework assignment.
• Homework

• Use the internet link below to access a game you
  can use to review graphing linear equations.

http//funbasedlearning.com/algebra/graphing/lines
/default.htm
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Use the link below to access a Lesson Quiz.
Good Luck!!
Be sure to submit all your work to your teacher
when completed!