1. 3.4 formulas
HW pg. 145 #1­22 1
October 07, 2011
Objective ­ use formulas
Evaluate each expression for
x = 3 and y = 4
1. 2x + 2y
2. 2x + y
3. x + y
2
Bellwork

2. 3.4 formulas
HW pg. 145 #1­22 2
October 07, 2011
formula ­ an equation that shows a relationship between
quantities that are represented by variables.
d = rt
Suppose you travel 162 miles in 3 hours. Use the formula
d = rt to find your average speed.

3. 3.4 formulas
HW pg. 145 #1­22 3
October 07, 2011
d = 273 mi, t = 9.75 h d = 540.75 in, r = 10.5 in/yr

4. 3.4 formulas
HW pg. 145 #1­22 4
October 07, 2011
You can estimate the temperature outside using the chirps of a cricket.
Use the formula where n is the number of times a cricket chirps per minute,
and F is the temperature in degrees Fahrenheit.
Estimate the temperature when a cricket chirps 100 times in a minute.
F = + 37
n
4

5. 3.4 formulas
HW pg. 145 #1­22 5
October 07, 2011
Perimeter ­
P = 2l + 2w
Find the perimeter of the room.
18.5 ft
12.5 ft

6. 3.4 formulas
HW pg. 145 #1­22 6
October 07, 2011
HW pg 145 # 1 ­ 22