Download Lesson 3-1B PowerPoint

(over Chapter 2)
Find –6 – (–12).
A. 18 B. 12 C. 6 D. –6
Find –5(11).
A. –55 B. –16 C. 16 D. 55
The temperature at 2:00 P.M. was 58ºF. By 9:00 P.M.
the temperature was 44ºF. What is the average
change in the temperature per hour?
1.
A
A. –14ºF
B. –7ºF
C. –2ºF
D. –1ºF
2.
3.
4.
B
C
D
(over Chapter 2)
Find –6 – (–12).
A. 18
B. 12
C. 6
D. –6
0%
0%
A
B
1.
2.
3.
4.
0%
C
A
B
C
D
0%
D
(over Chapter 2)
Find –5(11).
A. –55
B. –16
C. 16
D. 55
0%
0%
A
B
1.
2.
3.
4.
0%
C
A
B
C
D
0%
D
(over Chapter 2)
The temperature at 2:00 P.M. was 58ºF. By 9:00 P.M.
the temperature was 44ºF. What is the average
change in the temperature per hour?
A. –14ºF
B. –7ºF
0%
D
A
0%
A
B
C
0%D
C
D. –1ºF
1.
2.
3.
0%4.
B
C. –2ºF
Main Idea
Example 4: Real-World Example
Example 5: Test Example
• Write verbal phrases and sentences as simple
algebraic expressions and equations (2.8.8C)
(M7.D.2.1).
Add
Subtract
Added
Difference Multiplied Quotient
Plus
minus
Sum
Multiply
Divide
Product
Divided by
times
separate
FOOD An average American adult drinks
more soft drinks than any other beverage
each year. Three times the number of
gallons of soft drinks plus 27 is equal to
the total 183 gallons of beverages
consumed. Write an equation that
models this situation.
Words
Three times the number of gallons of soft
drink plus 27 equals 183.
Variable
Let s = the number of gallons of soft drinks.
Equation 3s + 27 = 183
Answer: The equation is 3s + 27 = 183.
EXERCISE It is estimated that American adults
spend an average of 8 hours per month exercising.
This is 26 hours less than twice the number of hours
spent watching television each month. Write an
equation that models this situation.
A. 8 – 2t = 26
D. 26 – 2t = 8
0%
D
A
0%
A
B
C
D
0%
C
C. 2t – 26 = 8
1.
2.
3.
4.
0%
B
B. 2t – 8 = 26
Which problem situation matches the equation
4.9y = 17.3?
A After giving away 4.9 kg of tomatoes, Harry had
17.3 kg left. What is y, the number of kg of tomatoes
that Harry began with?
B The total length of two toy cars is 17.3 cm. One car is
4.9 cm long. What is y, the length of the other car?
C A chemist separated a solution into 4 equal quantities
of 17.3 mL. What is y, the amount of solution she
began with?
D Rodrigo spent $17.30 on fishing line. If each meter of
line cost $4.90, what is y, the total length of the line?
Read the Item
You need to find which problem situation matches the
equation y ● 4.9 = 17.3.
Solve the Item
 You can eliminate choice A because it involves
subtraction, not multiplication.
 You can eliminate choice B because it involves
addition, not multiplication.
 You can eliminate choice C because it involves
multiplying 4 and 17.3.
 Choice D is the correct answer; the cost per meter
times the number of meters should equal the total
cost for the line.
Answer: D
Which problem situation matches the equation x – 7.5 = 22.4?
C.
A board measuring 22.4 cm in length is
cut into pieces. One of the pieces is 7 cm
longer than the other. Find the lengths of
the two pieces.
D.
Nicole lives 7.5 miles away from school.
She travels this distance in 22.4 minutes.
At what rate does Nicole travel?
1.
2.
3.
4.
0%
A
B
C
D
0%
0%
0%
D
Kevin spends $22.40 on video games.
His friend Aaron spends $7.50 more than
Kevin. How much did Aaron spend?
C
B.
B
The cost of a new book is $7.50. How
many books can Cori purchase is she
has a total of $22.40?
A
A.
REVIEW
1. The median age of people living in
Arizona (34.3) is 1 year younger than
the median age of people living in the
US. Write an equation to find the
median age in the US.
x – 1 = 34.3
Which problem situations matches the equation x –
15 = 46? B
A. The original price of a jacket is $46. The sale
price is $15 less. What is x, the sale price of the
jacket?
B. Mark had several baseball cards. He sold 15 of
the cards and had 46 left. What is x, the amount
of cards Mark had to start with?
C. Sonja scored 46 points in last week’s basketball
game. Talisa scored 15 points less. What is x,
the amount of points Talisa scored?
D. Katie earned $15 babysitting this week. Last
week she earned $46. What is x, her average
earnings for the two weeks?
TEST PRACTICE
1. Asha had some change in her purse.
After her brother gave her $.79, Asha
had $2.24 altogether. Which equation
can she use to find the original amount
of the money m she had in her purse?
A. 2.24 = m – 0.79 B. m =2.24 x 0.79
C. m + 0.79 = 2.24 D. m + 2.24 = 0.79
C
2. Which algebraic equation best
describes the total distance D traveled
in miles after a 6-hour period, if r
represents the rate of travel in miles
per hour?
F. D = 6 + r
G. D = r/6
H. D = 6r
I. D = 6/r
H
End of the Lesson
Five-Minute Check (over Chapter 2)
Image Bank
Math Tools
Solving Equations Using Models
Perimeter
Solving Equations
Two-Step Equations