Graphing Linear Equations

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Graphing Linear Equations

• In Standard Form
• Ax By C

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Linear equations have two variables and when we
plot all the (x,y) pairs that make the equation
true we get a line.
We will use The Standard Form of the equation
to graph the line.
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The formula for Standard Form is
Ax By C
We can find 3 things just by looking at the
formula
To find where the line crosses each axis, let
the other value be zero.

• If y is zero, we have Ax C
• is the x-intercept.
• If x is zero, we have By C
• is the y-intercept.
• - is the slope.

A B
Using the x-intercept and/or y-intercept as a
starting point, you can use the slope to graph
more points on the line of the equation.
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These equations are all in Standard Form
2x y -1 x y -4 3x 2y 4
Notice that these equations are all in the form
Ax By C.
5
2x y -1

• Find the x-intercept
• -1 2 -1/2
• 2) Find the y-intercept
• -1 -1 1
• 3) Plot the y-intercept.

4) Find the slope -A/B
- 2/-1 2 5) Plot more points using the slope.
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x y -4

• Find the x-intercept
• -4 1 -4
• 2) Find the y-intercept
• -4 1 -4
• 3) Plot the x and y-intercepts.

4) Find the slope -a/b
- 1/1 -1 5) Plot more points using the slope.
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A graph with only one letter (x or y) only
crosses that axis at that point.
y 5 ONLY crosses the y-axis at 5
x -3 ONLY crosses the x-axis at -3
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SUMMARY The formula for Standard Form is
Ax By C

• If y0, C A gives the
• x-intercept
• If x0, C B gives the
• y-intercept
• - is the
• slope

A B
Using the x-intercept and/or y-intercept as a
starting point, you can use the slope to graph
the line of the equation.