1. To Start: 20 Points!!
-2(4x + 3y – 4z – 11) 12(11) + 12(14) + 12(24) – 12(9) Use front-end estimation: Estimate the quotient: 29.5 ÷ 4.83
-8x – 6y + 8z +22
480
14.9 6

2. Chapter 3: Decimals and equations
Section 3.4: Using Formulas

3. Vocabulary
Formula is an equation that shows a relationship between quantities that are represented by variables. Example d=rt distance = rate x time The Perimeter of a figure is the distance around the figure. Example P=2w+2l

4. Using Formulas
Suppose you travel 162 miles in 3 hours. Use the formula d=rt to find your average speed. Distance is 162 miles, so d=162. Time is 3 hours, so t=3 162 miles = r(3 hours), so now solve for r. Divide each side by 3. r = 162/3 = 54 mph!!

5. Using d = r(t) d = 273 mi t = 9.75 hours 273 = r(9.75) r = 28 mph
d = in r = 10.5 in/yr = (10.5)t t = 51.5 yrs

6. Crickets!!! The temperature is about 62o
You can estimate the temperature outside using the chirps of a cricket. Use the formula F = n/4 + 37, where n is the number of chirps a cricket makes in one minute, and F is the temperature in degrees Fahrenheit. Estimate the temperature when a cricket chirps 100 times in a minute.
The temperature is about 62o

7. Crickets!!!
Use the formula to estimate the temperature in degrees Fahrenheit for 96 chirps per minute. The temperature is about 61o

8. Crickets – You Try!!!
Use the formula to estimate the temperature in degrees Fahrenheit for 88 chirps per minute. The temperature is about 59o

9. Crickets – You Try!!!
Use the formula to estimate the temperature in degrees Fahrenheit for 66 chirps per minute. The temperature is about 53.5o

10. Perimeter!!!!
Find the perimeter of the room, Use the formula for the perimeter of a rectangle.
12.5 ft
18.5 ft

11. Perimeter – You Try!!!!
Find the perimeter of the room, Use the formula for the perimeter of a rectangle.
16.8 cm
27.3 cm

12. Perimeter – You Try!!!!
Find the perimeter of the room, Use the formula for the perimeter of a rectangle.
8.6 in
17.4 in

13. Homework!!!
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