1. Chapter 5 Review

2. 5.1 Write Linear Eqns in Slope-Intercept Form
Example 1
Write an equation of the line shown.

3. Step 1: y = mx + b
Step 2: Find b.
(y-intercept)
b = 4
Step 3: Find m.
(slope = rise/run)
m = -2/3
Step 4: Write equation
y = (-2/3)x + 4

4. Assignment: Pg. 345
# 4 - 6

5. You have a $25 gift card for a bagel shop. A bagel costs $1. 25
You have a $25 gift card for a bagel shop. A bagel costs $1.25. Write an equation that gives the amount (in dollars) that remains on the card as a function of the total number of bagels you have purchased so far. How much money is on the card after you buy 2 bagels?
T = b (b= number of bagels, T = total)
T = (2) = $22.50

6. 5.2 Use Linear Equations in Slope-Intercept Form
Example 2
Write an equation of the line that passes through the point (-2,-6) and has a slope of 2.
Step 1: y = mx + b
Step 2: Find b (y-intercept)
y = mx + b
-6 = 2(-2) + b
-6 = -4 + b
-2 = b
Step 3: Write Equation
y = 2x - 2

7. Assignment: Pg. 346 #

8. 5.4 Write Linear Equations in Standard Form
Example 3
Write an equation in standard form of the line shown.
(-1,1) and m = -2

9. (-1,1) and m = -2 Step 1: y = mx + b Step 2: Find b 1 = (-2)(-1) + b
-1 = b
Step 3: Write equation
y = -2x - 1

10. Assignment: Pg. 347 #

11. 5.5 Write Equations of Parallel and Perpendicular Lines
Example 4
Write an equation of the line that passes through
(-4,-2) and is perpendicular to the line y = 4x - 7.
Hint: Perpendicular lines have slopes that are the negative reciprocal of each other.
Step 1: Find slope.
y = 4x -7
m = 4, so slope of perpendicular line is - 1/4.

12. Write an equation of the line that passes through (-4,-2) and is perpendicular to the line y = 4x - 7.
Step 2: Find b.
y = mx + b
-2 = (-1/4)(-4) + b
-2 = 1 + b
-3 = b
Step 3: Write Equation
y = (-1/4)x - 3

13. 5.5 Write Equations of Parallel and Perpendicular Lines
Example 5
Write an equation of the line that passes through
(-4,-2) and is parallel to the line
y = 4x - 7.
Hint: Parallel lines have the same slopes.
Step 1: Find slope.
y = 4x - 7
m = 4, so the slope of a parallel line is 4.

14. Write an equation of the line that passes through (-4,-2) and is parallel to the line y = 4x - 7.
Step 2: Find b.
y = mx + b
-2 = 4(-4) + b
-2 = b
14 = b
Step 3: Write equation.
y = 4x + 14

15. Assignment: Pg. 347 #

16. 5.6 Fit a Line of Data Example 6
The table shows the time needed to roast turkeys of different weights. Make a scatter plot of the data. Describe the correlation of the data.
Weight (pounds) 6 8 12 14 18 20 24
Roast time (hours)
2.75
3.00
3.50
4.00
4.25
4.75
5.25

17. Make a scatter plot of the data. Describe the correlation of the data.
Because the graph rises from left to right, it has a positive correlation

18. 5.6 Fit a Line of Data Step 1: Find the pattern on the data.
- positive correlation - rises from left to right.
- negative correlation - falls from left to right.
- no correlation - no real pattern.
Step 2: Draw line.
half the points above and half the points below.
Step 3: Write equation.
y = mx + b

19. Assignment: Pg. 348
# 21

20. 5.7 Predict with Linear Models
Example 7
Use the scatter plot from the example for Lesson 5.6 above to estimate the time (in hours) it takes to roast a 10 pound turkey.
Step 1: Draw scatter plot
Step 2: Draw Line of best fit.
Step 3: Find x-coordinate and y-coordinate on the line.

21. It takes about 3.25 hours to cook a 10 pound turkey.
Use the scatter plot from the example for Lesson 5.6 above to estimate the time (in hours) it takes to roast a 10 pound turkey.
It takes about 3.25 hours to cook a 10 pound turkey.

22. Assignment: Pg. 348
# 22

23. Assignment
Pg. 942 #2-8 even, even