Lines, Lines, Lines!!! ~ Slope-Intercept Form

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Lines, Lines, Lines!!!Slope-Intercept Form

• The meaning of Variables in a line

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Introduction

• A Line is composed of an infinite number of
  points puts together.
• All points fit the pattern of a single formula.
• There are several ways we could write the
  formula
• Standard Form
• Point-Slope Form
• Slope-intercept Form

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Slope intercept form is
y mx b
Our goal is to define each line where the y is
alone on one side of the equation.
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These equations are all in Slope-Intercept
Form
Notice that these equations are all solved for y.
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When an equation is in slope-intercept form
y mx b
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What is the slope? ____________
1
What is the intercept? ____________
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Now Try this Convert to Slope-Intercept Form
2y 26 -6x
Step 1 Subtract both sides by 26
Step 2 Divide both sides by 2 to get y by itself
Step 3 Simplify all fractions
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What is the slope? ____________
-13
What is the intercept? ____________
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When an equation is in slope-intercept form
y mx b
b y-intercept. This constant helps us
identified where to begin our graph. We start our
graph on this number of the y-axis. The
y-intercept tells us that the line crosses the
y-axis at this point. m slope. This constant
is always the coefficient of the x variable.
It helps us find all of the remaining points of
the line
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On the next three slides we will graph the three
equations
using their y-intercepts and slopes.
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1. Plot the y-intercept as a point on the
y-axis. The constant b 1, so the y-intercept
1.
2. Plot more points by counting the slope up the
numerator and to the right denominator. The
coefficient m 2, so the slope 2/1.
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1. Plot the y-intercept as a point on the
y-axis. The constant b -4, so the y-intercept
-4.
2. Plot more points by counting the slope up the
numerator and right the denominator. The
coefficient m -1, so the slope -1/1.
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1. Plot the y-intercept as a point on the
y-axis. The constant b -7, so the y-intercept
-7.
2. Plot more points by counting the slope up the
numerator and to the right denominator. The
coefficient m 5/3, so the slope 5/3.
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• Graph the following equations

They look different but they are not
different. Before we can graph them, it is always
best to set them us in the Slope-intercept
Form y mx b
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The constant b 8 is the y-intercept.
The coefficient m 3/2 is the slope.
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Or
The constant b 1 is the y-intercept.
The coefficient m 9/7 is the slope.
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The constant b -3 is the y-intercept.
The coefficient m -6/5 is the slope.
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The new modified equations are
Now you will have a much easier time graphing
these equations Now your turn to graph
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Student Activity

• You will now receive a worksheet. Turn the
  worksheet in when completed.

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Do Not Disturb Work In Progress