1. Fri, 12/15/10
WARM-UP: TO BE COLLECTED! 1.) Find the slope of the following points (2a, 3b) and (5a, 6b)
2.) Dave graphs the functions y = x – 3 and y = 4x + 1 on the same State two ways the graphs are different. set of coordinate axes. Explain the reason for each difference.
HW: CATCH UP! REVIEW PAST NOTES, HW, TESTS, QUIZZES, ETC!
~50% of the class is between grades (88%-92%, 78-82%, etc)
1.) b/a
2.) The graph of the line y = x – 3 will cross the y-axis at -3 and the graph of the line of y = 4x + 1 will cross the y-axis at 1. This is because the y-intercept of y = x – 3 is -3 and the y-intercept of y = 4x + 1 is 1.
The graph of the line y = x – 3 will be less steep than the graph of the line y = 4x This is because the slope of the line y = x -3 is 1 and the slope of the line y = 4x + 1 is 4. If the slope is greater, the line is steeper.

2. Families of linear graphs

3. SWBAT… Write equations in slope-intercept form Mon, 1/3
Agenda
WU (10 min)
3 practice problems to refresh our memories! (10 min)
Notes on writing equations of lines (2 examples) (25 min)
Start on hw (5 min)
WARM-UP:
1. Write the homework in your planner
2. Find the slope of Ax + By = C
3. Solve for y: 5x + 4y = 80
HW#5: Writing Eqns of lines in Slope-Intercept Form
1.) m = -A/B
2.) y = -5/4x + 20

4. 1/3 What is the slope of 5x + 4y = 80 A. m = -5 x B. m = -5 C. m = -4
D. m = - 5
m = -5/4

5. Which equation(s) has the same y-intercept as y = ½x + 2?
2/3
Which equation(s) has the same y-intercept as y = ½x + 2?
A. y = 2x + 4
B. 2 – y = ½x
C. y – 2 = x
D. y = x
b = 2
Answer: B and C

6. Which equation is parallel to the line -2x + 4y = 3?
3/3
Which equation is parallel to the line -2x + 4y = 3?
A. y = -1/2 x + 5
B. y = 2x – 6
C. y = -2x + 4
D. y = ½x – 2
Parallel lines have the SAME slope.
Answer: D (m = ½)

7. Quiz Writing equations of lines Writing equations of lines
Monday, 1/3
Tuesday, 1/4
Wednesday, 1/5
Thursday, 1/6
Friday, 1/7
Writing equations of lines
Writing equations of
lines
Quiz
Point slope form &
Standard form
Lines of best fit activity
All 3 forms of lines
1. Slope-intercept
2. Point-slope
3. Standard
Monday, 1/10
Tuesday, 1/11
Wednesday, 1/12
Thursday, 1/13
Friday, 1/14
Parallel and
perpendicular
Lines
TBD
Monday, 1/17
Tuesday, 1/18
Wednesday, 1/19
Thursday, 1/20
Friday, 1/21
MLK
NO CLASSES
Final review
Finals – evens
ALGEBRA FINAL
Part I
Finals – odds
ALGEBRA FINAL Part II
Monday, 1/24
Tuesday, 1/25
Wednesday, 1/26
Thursday, 1/27
Friday, 1/28
END OF Q2/S1

8. Quiz Writing equations of lines Writing equations of lines
Monday, 1/3
Tuesday, 1/4
Wednesday, 1/5
Thursday, 1/6
Friday, 1/7
Writing equations of lines
Writing equations of
lines
Quiz
Point slope form &
Standard form
Scantron
TESTING
All 3 forms of lines
1. Slope-intercept
2. Point-slope
3. Standard
Monday, 1/10
Tuesday, 1/11
Wednesday, 1/12
Thursday, 1/13
Friday, 1/14
Parallel and
perpendicular
Lines
Infinity teachers project
Monday, 1/17
Tuesday, 1/18
Wednesday, 1/19
Thursday, 1/20
Friday, 1/21
MLK
NO CLASSES
Final review
Finals – evens
ALGEBRA FINAL
Part I
Finals – odds
ALGEBRA FINAL Part II
Monday, 1/24
Tuesday, 1/25
Wednesday, 1/26
Thursday, 1/27
Friday, 1/28
END OF Q2/S1

9. 1. Set-up Cornell notes. Topic is “writing equations of lines in slope-intercept form”
2. Example 1: Write the equation of the line, in slope-intercept form, that passes through (3, 5) and (5, 9)
3. Plot (3, 5) and (5, 9) on a graph paper square and paste in your note book. Using your graph, write the equation of the line.

10. y = mx + b y = mx+ b is an equation that defines a line
A line has two characteristics:
1.) Slope
2.) Points that fall on the line
To write the equation of a line, you need:
1.) The slope of the line
2.) ANY point on the line

11. Ex1:
Write the equation of the line, in slope-intercept form, that passes through (3, 5) and (5, 9)
m = (y2-y1)/(x2-x1)
Step 1: Find the slope
m = (9-5)/(5-3) = 4/2 = 2
Step 2: Plug in either coordinate into y = mx + b and solve for b
(3, 5) (5, 9)
y = mx + b y = mx+b
5 = 2(3) + b OR = 2(5) + b
5 = 6 + b = 10 + b
-1 = b = b
Step 3: Write the equation of the line by substituting the values you computed for m (step 1) and b (step 2) in y = mx + b
y = mx + b
y = 2x – 1
Besides (3, 5) and (5, 9), what’s another point on this line?
Hint: b=-1
(0, -1)

12. Ex2:
Write the equation of the line, in slope-intercept form, with a slope of 10 that passes through (-1, -4)
m = 10
Step 1: Find the slope
Step 2: Plug in either coordinate into y = mx + b and solve for b
(-1, -4)
y = mx + b
-4 = 10(-1) + b
-4 = b
-6 = b
Step 3: Write the equation of the line by substituting the values you computed for m (step 1) and b (step 2) in y = mx + b
y = mx + b
y = 10x – 6
Besides (-1, 4) what’s another point on this line?
(0, -6)

13. SWBAT… Write equations in slope-intercept form Tues, 1/4
Agenda
WU (15 min)
Review hw#5 (15 min)
Quiz (15 min)
WARM-UP:
Write the slope-intercept form of an equation of the line that satisfies each condition:
1.) Has slope 3 and y-intercept -5
2.) Passes through (5, -7) and has a slope of 3
3.) Passes through (6, -3) and (12, -3)
4.) Has an x-intercept of -2 and a y-intercept of 4 (Hint: write the two points)
2 problems
1. y = 3x – 5
2. y = 3x – 22
3. y = -3
4. y = 2x + 4 (the two points are (-2, 0) and (0, 4))

14. HW#5: Answers Y = 5x – 20 Y = 3/4x – 2 Y = 10x + 6 Y = 2/7x - 2 4/7D B C
a: C = 0.06y
19. b: $7.26
C x represents the number of tickets per order, y represents the total cost of the order
B x represents the numbers of tickets sold, y represents the total amount of money
20. A x represents the number of days, y represents the total depth of water in the pool in inches

15. Tuesday, 1/4/11: Homework:
1. Consider the points (3, 7), (-6, 1) and (9, p) on the same line. Find the value of p.
2. The x-intercept of a line is p, and the y-intercept is q. Write an equation of the line in slope-intercept form.
p = 11
y = -q/p + q