1. 5-3A Vocabulary 5.) Linear equation 6.) y-intercept 7.) Slope-intercept form

2. 5-3A Slope Intercept Form Algebra I

3. Slope Intercept Form y = mx+b where m = slope b = y-intercept

4. Ex. 1 Identifying slope & y-intercept Ex. 1) What are the slope & y-intercept of the graph of y = 3x-6?

5. Ex. 2 Writing an equation in slope intercept form. Ex. 2) What is an equation of the line with m = 5 and b = 8?

6. Ex. 3) Given the graph or picture, use the equation y=mx+b Ex. 3 The y-intercept is -3 b=-3 The slope is 4/3 The equation is: 4 3

7. Given two points 1) Use slope formula first to find slope. 2) Plug the slope discovered from step #1 and one of the points into the slope intercept formula. 3) Lastly, plug the slope from step #1 & the b value or y –intercept from step #2 into y=mx + b.

8. Ex. 4 Given two points (1,-6) & (-3,10) write the equation of the line 1 st - Find the slope: m= __ 2 nd - Plug this slope and one of the points into the slope intercept formula. y=mx+b3 rd y=mx+b

9. Bellwork

10. 5-3B Graphing linear equations Ex. 5) Graph y = -3x - 2

11. Ex. 6) Find the slope & y-intercept of the graph of each equation.

12. Ex. 7) Graph 3y + 9 = 2x

13. Assignment

14. Write equations of parallel or perpendicular lines Ex. 4 Write an equation of the line that passes through (-2,1) and is –a.)parallel to y = -3x + 4

15. Ex. 4 Write an equation of the line that passes through (-2,1) and is b.) perpendicular to y = -3x + 4

16. Ex. 5 Write a model using slope-intercept form The number of U.S. cell phone subscribers increased from 16 million in 1993 to 44 million to 1996. Find the average rate of change and use it to estimate the number of subscribers in 1997.

17. Ex. 6 Write a model using standard form You have $6 to spend on drinks and a salad at the school cafeteria. The drinks cost $1.25 each and the salad costs $.20 per ounce. Write an equation that models this situation.

18. B.) If you are given slope, m, and a point (x 1,y 1 ) on the line Use Point Slope Form: y – y 1 = m ( x – x 1 )

19. Ex. 2 Write an equation of a line containing the point (1,2) with slope of -1/2. Use (x 1,y 1 ) = (1,2) & m = -1/2 y – 2 = -1/2 ( x – 1) Now you can simplify to the slope intercept form y – 2 = -1/2 x + ½ y = -1/2 x + 5/2