SWBAT…write algebraic equations from data

Agenda

1. WU (5 min)

2. Writing algebraic equations from data (40 min)

1. Pick up an agenda from the front table.

2. Write your homework and quiz in your planner for the week.

HW#7: Algebraic Linear Equations from Data

Tues, 9/27

1. The table shows the cost C of renting a boat for h hours.

Which equation best represents the data?

1.) C = 7.25h 3.) C = 21.25 – 7.25h

2.) C = h + 7.25 4.) 7.25h + 21.25

Hours 1 2 3

Cost ($) 7.25 14.5 21.75

2. The table shows the total amount of rain during a storm. Write a formula to find out how much rain will fall after a given hour.

1.) h = 0.45n 2.) n = 0.45h

3.) h = 0.9 4.) h = 1.8n

Hour (h) 1 2 3 4

Inches (n) 0.45 0.9 1.35 1.8

Number of Hours (n) Labor Charges (C) 1 $60 2 $85 3 $110 4 $135

Which function represents the situation?1.) C(n) = 25n + 35 2.) C(n) = 25n + 303.) C(n) = 35n + 25 4.) C(n) = 35 + 40

3. The table shows the labor charges of an electrician for jobs of different lengths.

4. A company sells candy bars. The table below shows the total weight of a box with 1, 2, 3, and 4 candy bars.

Number of candy bars in box

Total weight in (ounces)

1 9.5

2 15.5

3 21.5

4 27.5

a. Write an algebraic rule that can be used to determine the total weight of the box for any number of candy bars. Show or explain your work.

b. Describe what each number and variable represents in your algebraic rule.

HW#7: Answers5. a.) P = 4s

b.) The perimeter is 4 times the side length.

6. a.) C = 1.25p

b.) C = $7.50

7. a.) b = 45c

b.) b = $360

8. a.) y = 3x + 6

9. b.) h = 15t + 60

c.) h = 180 ft

10. a.) M = 1.5w + 7b.) M = 25. No, she will not reach her goal; she will miss her goal by one mile.

11. a.) Db.) y = -3(10) + 256 = 226 pencils

12.

b.) The function is not linear because the number of rectangles does not increase by a constant amount each time there is another fold.c.) At 6 folds there will be 64 rectangles.

At 7 folds there will be 128 rectangles. At 8 folds there will be 256 rectangles.I continued this pattern of multiplying by 2 until the 8 th fold.

Number of folds Number of rectangles

2 4

3 8

4 16

5 32

13.

14.

15.

A growing T-pattern made of small square tiles is shown below.

Write an algebraic rule for the total number of tiles, T, in terms of the figure, n.

Figure 1 Figure 2 Figure 3

A construction company sells tiles in one size. The table below shows the perimeter when one, two, three and four tiles are fit together.

Number of tiles (t)

Picture of tile Perimeter of tile (P)

1 4

2 6

3 8

4 10

a. Write an algebraic rule for the perimeter.

b. Using this table, what would you predict is the perimeter of a border with eight tiles?

Warm-UpThe total cost for a plumbing job is determined by a one-time fee of $145 plus $65 per hour worked plus the cost of parts.

a. Write an algebraic rule that can be used to determine the total cost.

b. Describe what each number and variable represents in your algebraic rule. (BE SPECIFIC!