Algebra 1 Section 4.6

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Algebra 1Section 4.6
Quick Graphs Using Slope-Intercept Form

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Important!!!

• This is a big concept in Algebra 1. You need to
  thoroughly understand this!
• Slope Intercept Form
• y mx b
• m represents the slope
• b represents the y-intercept

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Writing Equations

• When asked to write an equation, you need to know
  two things slope (m) and y-intercept (b).

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Example 1 Writing Equations

• Write an equation in slope-intercept form of the
  line that has a slope of 2 and a y-intercept of
  6.
• To write an equation, you need two things
• slope (m)
• y intercept (b)
• We have both!! Plug them into slope-intercept
  form
• y mx b
• y 2x 6

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6
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Writing Equations

• Write an equation in slope-intercept form for the
  following
• 1. 3.
• 2. 4.

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Write the equation of a line that has a
y-intercept of -3 and a slope of -4.

1. y -3x 4
2. y -4x 3
3. y -3x 4
4. y -4x 3

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To find the slope and y-intercept of an equation,
write the equation in slope-intercept form y
mx b.

• Find the slope and y-intercept.
• y 3x 7
• y mx b
• m 3, b -7

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Find the slope and y-intercept.

• 2) y x
• y mx b
• y x 0
• 3) y 5
• y mx b
• y 0x 5

m b 0
m 0 b 5
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Find the slope and y-intercept.4) 5x - 3y 6

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m b -2
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Find the slope and y-intercept. 5) 2y 2 4x

• Write it in slope-intercept form.
• (y mx b)
• 2y 2 4x
• - 2 - 2
• 2y 4x 2
• 2 2 2
• y 2x - 1

m 2 b -1
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Find the slope and y-intercept of y -2x 4

1. m 2 b 4
2. m 4 b 2
3. m -2 b 4
4. m 4 b -2

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Example 2 Graphing Using Slope and y-Intercept

• When given an equation, you can easily graph it
  in slope-intercept form. All you need is two
  things
• the slope (m) and y-intercept (b).

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Graphing Using Slope and y-intercept

• Step 1 Make sure the equation is in
  slope-intercept form
• Step 2 Find the slope and y-intercept
• Step 3 Plot the y-intercept
• Step 4 Apply the slope (rise/run) to the
  y-intercept

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Review Graphing with slope-intercept
-3
-3
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1. Start by graphing the y-intercept (b 2).
2. From the y-intercept, apply rise over run using
   your slope.rise 1, run -3
3. Repeat this again from your new point.
4. Draw a line through your points.

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Start here
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Graph
Step 1 ymxb Step 2 slope 2 y-intercept
3 Step 3 plot the y-intercept on a graph Step
4 apply the slope
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Graph the following equations
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HomeworkComplete Study Guide for Chapter 4 ?
due Tuesday, November 19th