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OBJECTIVES:
1. Write an equation of a line, given its slope and y-intercept. 2. Graph a line, using its slope and y-intercept. 3. Write an equation of a line, given its slope and a point on the line. 4. Write an equation of a line, given two points on the line. 5. Write an equation of a line parallel or perpendicular to a given line. 6. Write an equation of a line that models real data.
1.
Copyright © 2010 Pearson Education, Inc. All rights reserved
Sec 4.3 - 1
2.
Chapter 4
Graphs, Linear Equations,
and Functions
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Sec 4.3 - 2
3.
4.3
Linear Equations in Two
Variables
Copyright © 2010 Pearson Education, Inc. All rights reserved
Sec 4.3 - 3
4.
4.3 Linear Equations in Two Variables
Objectives
1. Write an equation of a line, given its slope and y-
intercept.
2. Graph a line, using its slope and y-intercept.
3. Write an equation of a line, given its slope and a
point on the line.
4. Write an equation of a line, given two points on
the line.
5. Write an equation of a line parallel or
perpendicular to a given line.
6. Write an equation of a line that models real data.
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 4
5.
4.3 Linear Equations in Two Variables
Write an equation of a line given its slope and y-intercept.
Given the slope m of a line and the y-intercept b of the
line, we can determine its equation.
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 5
6.
4.3 Linear Equations in Two Variables
Write an equation of a line given its slope and y-intercept.
If we know the slope of a line and its y-intercept, we can
write its equation by substituting these values into the
above equation.
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 6
7.
4.3 Linear Equations in Two Variables
Writing an Equation of a Line
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 7
8.
4.3 Linear Equations in Two Variables
Graph Lines Using Slope and y-Intercept
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 8
9.
4.3 Linear Equations in Two Variables
Write an equation of a line, given its slope and a point on the line.
If we know the slope m of a line and the coordinates of a
point on the line, we can determine its equation.
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 9
10.
4.3 Linear Equations in Two Variables
Write an equation of a line, given its slope and a point on the line.
If we know the slope of a line and the coordinates of a
single point on the line, we can write the equation of the
line by substituting these values into the equation above.
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 10
11.
4.3 Linear Equations in Two Variables
Finding the Equation of a Line, Given the Slope and a Point
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 11
12.
4.3 Linear Equations in Two Variables
Finding an Equation of a Line, Given Two Points
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 12
13.
4.3 Linear Equations in Two Variables
Finding an Equation of a Line, Given Two Points
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 13
14.
4.3 Linear Equations in Two Variables
Equations of Horizontal and Vertical Lines
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15.
4.3 Linear Equations in Two Variables
Finding Equations of Parallel or Perpendicular Lines
Recall that parallel lines have the same slope and
perpendicular lines have slopes with product –1.
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 15
16.
4.3 Linear Equations in Two Variables
Finding Equations of Parallel or Perpendicular Lines
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 16
17.
4.3 Linear Equations in Two Variables
Finding Equations of Parallel or Perpendicular Lines
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 17
18.
4.3 Linear Equations in Two Variables
Finding Equations of Parallel or Perpendicular Lines
6
–6 6
–6
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19.
4.3 Linear Equations in Two Variables
Finding Equations of Parallel or Perpendicular Lines
Recall that parallel lines have the same slope and
perpendicular lines have slopes with product –1.
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 19
20.
4.3 Linear Equations in Two Variables
Finding Equations of Parallel or Perpendicular Lines
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 20
21.
4.3 Linear Equations in Two Variables
Finding Equations of Parallel or Perpendicular Lines
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 21
22.
4.3 Linear Equations in Two Variables
Finding Equations of Parallel or Perpendicular Lines
6
–6 6
–6
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23.
4.3 Linear Equations in Two Variables
Forms of Linear Equations
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 23
24.
4.3 Linear Equations in Two Variables
Determining a Linear Equation to Describe Real Data
A veterinarian charges $45 to visit a farm where cattle are
raised. The price to vaccinate each animal is $18. Write
an equation that defines the total bill that the veterinarian
will submit to vaccinate all the cattle at the farm.
Copyright © 2010 Pearson Education, Inc. All rights reserved. Sec 4.3 - 24
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