1. Chapter 2 – Linear Equations and Functions 2.5 – Writing Equations of Lines

2. In this section we will review: –Writing linear equations

3. 2.5 – Writing Equations of Lines If you know: –Slope (m) and y – intercept (b), you can use slope – intercept form y = mx + b –Slope (m) and any point on the line (x 1, y 1 ), you can use point – slope form y – y 1 = m (x – x 1 )

4. 2.5 – Writing Equations of Lines Example 1 –Write an equation of the line shown

5. 2.5 – Writing Equations of Lines Example 2 –Write an equation of the line shown

6. 2.5 – Writing Equations of Lines Example 3 –Write an equation of the line that passes through (9, 2) and has a slope of -1 3

7. 2.5 – Writing Equations of Lines Example 4 –Write an equation of the line that passes through (-1, 0) and has a slope of 2.

8. 2.5 – Writing Equations of Lines Example 5 –Write an equation of the line that passes through (2, 1) and is parallel to the line y = 3x + 10.

9. 2.5 – Writing Equations of Lines Example 6 –Write an equation of the line that passes through (2, 1) and is perpendicular to the line y = 3x + 10.

10. 2.5 – Writing Equations of Lines Example 7 –Write an equation of the line that passes through (-6, 3) and is parallel to the line y = ½ x + 4.

11. 2.5 – Writing Equations of Lines Example 8 –Write an equation of the line that passes through (-6, 3) and is perpendicular to the line y = ½ x + 4.

12. 2.5 – Writing Equations of Lines Example 9 –At the end of 2006 the number of children enrolled in an after-school activity was 350. At the beginning of 1997 the number of children enrolled in the activity was 180. Write a linear model that represents the number of children enrolled in the activity between 1997 and 2006.

13. 2.5 – Writing Equations of Lines Example 10 –In 2003, a house was valued at $250,000. In 2009, the same house was valued at $205,000. Write a linear model for the value v of the house for the period 2003 to 2009 where t represents the number of years since 2003.

14. 2.5 – Writing Equations of Lines HOMEWORK Worksheet 2.5