1. Copyright © 2010 Pearson Education, Inc. All rights reserved Sec 4.3 - 1 3.3 Linear Equations in Two Variables

2. Copyright © 2010 Pearson Education, Inc. All rights reserved. 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.

3. Copyright © 2010 Pearson Education, Inc. All rights reserved. Linear Equations in Two Variables Writing an Equation of a Line

4. Copyright © 2010 Pearson Education, Inc. All rights reserved. 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.

5. Linear Equations in Two Variables Finding the Equation of a Line, Given the Slope and a Point

6. Linear Equations in Two Variables Finding an Equation of a Line, Given Two Points

7. Copyright © 2010 Pearson Education, Inc. All rights reserved. Linear Equations in Two Variables Equations of Horizontal and Vertical Lines

8. 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.

9. Copyright © 2010 Pearson Education, Inc. All rights reserved. Linear Equations in Two Variables Finding Equations of Parallel or Perpendicular Lines 6 –6–6 6 –6–6

10. 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.

11. Copyright © 2010 Pearson Education, Inc. All rights reserved. Linear Equations in Two Variables Finding Equations of Parallel or Perpendicular Lines 6 –6–6 6 –6–6

12. Copyright © 2010 Pearson Education, Inc. All rights reserved. Linear Equations in Two Variables Forms of Linear Equations