# finding slope and writing equations in slope-intercept form

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Finding Slope and Writing Equations in Slope-intercept Form. Standard: A.CED.2 (Algebra. Creating Equations.). Essential Questions. How do I find slope using the slope formula? How do I rewrite an equation in slope-intercept form? How do I identify the slope and the y-intercept?. - PowerPoint PPT PresentationTRANSCRIPT

Finding Slope and Writing Equations in Slope-intercept Form

Standard: A.CED.2(Algebra. Creating Equations.)

Essential Questions

• How do I find slope using the slope formula?• How do I rewrite an equation in slope-

intercept form?• How do I identify the slope and the y-

intercept?

Finding Slope

12

12

xx

yy

M =

Example 1:

Find the slope using the following points:

A line contains the points (–1, 3) and (2, –3).

Find m. m =–3 – 3

2 – (–1)

–6

3= –2=

Example 2:

Find the slope: (-4, -2) and (2, -2)

The slope of a horizontal line is ZERO!

Example 3:

Find the slope: (1, 4) and (1, -3)

The slopes of vertical lines are UNDEFINED!

Example 4:

Find the slope: (4, -2) and (-2, 6)

Example 5: Signs of slope

Positive, negative, zero, or undefined:

QUICKLY:

Textbook pg. 25, #’s 1-3 all, 14-26 EVEN

Pg. 25, #’s 1-3, 14-26 EVEN

1. Positive2. Negative3. Undefined14. -4/516. -3/518. Undefined20. ½22. -1/4

24. 126. 1

Writing Equations and Identifying “m” and “b”

y = mx + bm = slopeb = y-intercept**If an equation is not in slope-intercept form,

just get “y” by itself. Then, identify the “m” and the “b”.

Example 1

• Write an equation for the given information in slope-intercept form:

• M = 2, b = 3• Y = 2x + 3• M = -3, b = -4• Y = -3x – 4• M = ½, b = -5• Y = ½ x - 5

Example 2:

• Write the equation in slope-intercept form, then identify the m and the b:

• -2x + 3y = 9

Example 3

• Write the equation in slope-intercept form, then identify the m and the b:

• 4x + y = 3

Example 4:

• Write the equation in slope-intercept form, then identify the m and the b:

• 5x – 4y = 12

Example 5:

• Write the equation in slope-intercept form, then identify the m and the b:

• 2x – y = 3

QUICK!

Textbook pg. 32, #’s 2-12 EVEN and #14 and #15

Pg. 32, 2-12 EVEN, 14-15

2. 3/2; 14. 5; -46. -9; 88. 3; -110. 3; 1/312. ¼; 5/814. 0; -415. undefined; none

Homework:

• Workbook pg. 25-27, #’s 1-30 ALL• Workbook pg. 32 #’s 1-12 ALL

• SHORT GRAPHING AND INTERCEPT QUIZ THE NEXT TIME YOU COME IN HERE!!!

Pg. 25-27

1. Neg2. Undefined3. Pos4. Zero5. Pos6. Neg7. Pos8. Zero9. Neg10. Pos

11. Undefined12. Neg13. 114. -215. 016. -117. Undefined18. 219. 3/220. -1/2

Continued…

21. Undefined22. 123. -524. 325. -226. -627. 128. -2

29. 030. undefined

Pg. 32, #’s 1-12

1. 2; 12. 2/3; 13. -1/2; 24. 2; 25. ½; -16. 3/2; 17. 3; 48. 5; -29. -2; 8

10. ½; 011. -3/4; -112. 4; 4