Holt CA Course 2

Writing Algebraic Expressions1-2

AF1.1 Use variables and appropriate operations to write an expression, an equation, an inequality, or a system of equations or inequalities that represents a verbal description (e.g., three less than a number, half as large as area A).

California Standards

Holt CA Course 2

Writing Algebraic Expressions1-2

• a number plus 5• sum of a number and 5• 5 more than a number• subtract 11 from a number

• difference of a number and 11

• 11 less than a number

• 3 multiplied by a number

• product of 3 and a number

• 7 divided into a number

• quotient of a number and 7

n + 5

x – 11

3 m or 3m

or a 7a7

Word Phrases Expression

+

–

Holt CA Course 2

Writing Algebraic Expressions1-2

Write an algebraic expression for each word phrase.

Additional Example 1: Translating Word Phrases into Math Expressions

A. 9 less than a number w 9 less than a number ww – 9w – 9

B. 3 increased by the difference of p and 53 increased by the difference of p and 53 + (p – 5)3 + (p – 5)

Holt CA Course 2

Writing Algebraic Expressions1-2

Write an algebraic expression for each word phrase.

Check It Out! Example 1

A. 88 times the difference of h and 4

88 times the difference of h and 488 • (h – 4)

88(h – 4)

B. the quotient of a number f and 6quotient of f and 6f 6

f6

Holt CA Course 2

Writing Algebraic Expressions1-2

Write a word phrase for the algebraic expression 9 – 3c.

Additional Example 2: Translating Math Expressions into Word Phrases

9 – 3c

9 – 3 • c

9 minus the product of 3 and c

9 minus the product of 3 and c

Holt CA Course 2

Writing Algebraic Expressions1-2Check 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

Holt CA Course 2

Writing Algebraic Expressions1-2

To solve a word problem, first interpret the action you need to perform and then choose the correct operation for that action.

Holt CA Course 2

Writing Algebraic Expressions1-2

A restaurant leased its banquet hall for a function. The cost was $10 per person. Write an algebraic expression to determine what the cost would be if n people attended the function. Then evaluate the expression for 20, 21, 22, or 23 people.

Additional Example 3: Writing and Evaluating Expressions in Word Problems

$10 • n Combine n equal amounts of $10. 10n Cost in dollars

20 10(20) $200 21 10(21) $210 22 10(22) $220 23 10(23) $230

Evaluate for n = 20, 21, 22, and 23.

n 10n Cost