Warm Up

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Warm Up
Problem of the Day
Lesson Presentation
Lesson Quizzes
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Warm Up Evaluate each expression for the given
values of the variables. Which operation
symbol goes with each word?
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1. 9y 13 for y 4
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2. 6n 2p for n 2 and p 3
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3. 3x y for x 1 and y 2

4. Sum
?
5. Product
?
6. Quotient

7. Difference
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Problem of the Day Find a pair of numbers that
fits the description. Their product is 221 and
their sum is 30.
13, 17
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Learn to translate between algebraic expressions
and word phrases.
5

• a number plus 5

• add 5 to a number

n 5

• sum of a number and 5

• 5 more than a number

• a number increased by 5

• a number minus 11

• subtract 11 from a number

x 11

• difference of a number and 11

• 11 less than a number

• a number decreased by 11

• 3 times a number

• 3 multiplied by a number

3m

• product of 3 and a number

• a number divided by 7

• 7 divided into a number

• quotient of a number and 7

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Additional Example 1 Translating Word Phrases
into Math Expressions
Write an algebraic expression for each word
phrase.
A. 9 less than a number w
9 less than a number w
w 9
w 9
B. 3 increased by the difference of p and 5
3 increased by the difference of p and 5
3 (p 5)
3 p 5
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Check It Out Example 1
Write an algebraic expression for each word
phrase.
A. the sum of a number h and 88 minus 4
the sum of h and 88 minus 4
h 88 4
h 88 4
B. the quotient of a number f and 6
quotient of f and 6
f ? 6
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Additional Example 2 Translating Math
Expressions into Word Phrases
Write a word phrase for the algebraic expression
9 3c.
9 3c
9 3 c
9 minus the product of 3 and c
9 minus the product of 3 and c.
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Check It Out Example 2
Write a word phrase for the algebraic expression
7 19b.
7 19b
7 19 b
7 plus the product of 19 and b
7 plus the product of 19 and b.
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To solve a word problem, first interpret the
action you need to perform and then choose the
correct operation for that action.
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Additional Example 3 Writing and Evaluating
Expressions in Word Problems
A restaurant leased its banquet hall for a
function. The cost was 10 per person. Write an
algebraic expression to evaluate what the cost
would be if 20, 21, 22, or 23 people attended the
function.
10 dollars n
Combine n equal amounts of 10.
10n
In dollars
Evaluate for n 20, 21, 22, and 23.
20 10 20 200
21 10 21 210
22 10 22 220
23 10 23 230
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Check It Out Example 3
Gasoline costs 3.59 per n gallons. What will the
cost be for 10, 12, 14, and 15 gallons?
3.59 n
Combine n equal amounts of 3.59.
3.59n
In dollars
10 3.59 10 35.90
Evaluate for n 10, 12, 14, and 15.
12 3.59 12 43.08
14 3.59 14 50.26
15 3.59 15 53.85
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Additional Example 4 Writing a Word Problem from
a Math Expression
Write a word problem that can be evaluated by the
algebraic expression 27 t, and evaluate the
expression for t 1.76.
Possible Answer Amed bought a new sweater for
27 plus sales tax t. If the tax was 1.76, what
was the total cost of the sweater?
27 t
27 1.76 28.76
Substitute 1.76 for t.
The total cost of the sweater was 28.76.
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Check It Out Example 4
Write a word problem that can be evaluated by the
algebraic expression 43 d, and evaluate the
expression for d 10.24.
Possible Answer Tina bought a new jacket for
43 minus a store credit. If the store credit was
10.24, what was the total cost of the jacket?
43 d
43 10.24 32.76
Substitute 10.24 for t.
The total cost of the jacket was 32.76.
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Lesson Quizzes
Standard Lesson Quiz
Lesson Quiz for Student Response Systems
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Lesson Quiz
Write an algebraic expression for each word
phrase. 1. 5 less than a number k 2. a number x
divided by 11 3. 4 times the sum of n and 5 Write
an algebraic expression to evaluate the word
problem. 4. Karen buys n raffle tickets for
0.50 each. If she buys 13 of them, how much
will they cost?
k 5
4(n 5)
0.50n 6.50
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Lesson Quiz for Student Response Systems

• Identify the algebraic expression for the given
  word phrase.
• 20 less than a number r

A. 20 r
B. r 20
C. 20r r
D. 20 20r
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Lesson Quiz for Student Response Systems
2. Identify the algebraic expression for the
given word phrase. a number p divided by 16
16p p
p 16
A.
B.
p 16p
C.
D.
16 p

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Lesson Quiz for Student Response Systems
3. Identify the algebraic expression for the
given word phrase. 6 times the sum of r and
9

A. 6 r 9
B. 6r 9
C. r(6 9)
D. 6(r 9)
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Lesson Quiz for Student Response Systems
4. Identify the algebraic expression that
evaluates the given word problem. Alice buys
x apples for 0.75 each. If she buys 24 of them,
how much will they cost?

A. 0.75x 9
B. 24x 9
C. 0.75x 18
D. 24x 18