Holt CA Course 1 1-6Writing Algebraic Expressions OperationVerbal Expressions Algebraic Expressions add 3 to a number a number plus 3 the sum of a number and 3 3 more than a number a number increased by 3 subtract 12 from a number a number minus 12 the difference of a number and less than a number a number decreased by 12 take away 12 from a number a number less than 12 n + 3 x – 12 WRITE THESE IN THE BLANK SPACE

Holt CA Course 1 1-6Writing Algebraic Expressions OperationVerbal Expressions Algebraic Expressions 2 times a number 2 multiplied by a number the product of 2 and a number 6 divided into a number a number divided by 6 the quotient of a number and 6 2m or 2 m ÷ a6a6 ÷ 6 or a WRITE THESE IN THE BLANK SPACE

Holt CA Course 1 1-6Writing Algebraic Expressions Example 1: Translating Verbal Expressions into Algebraic Expressions Write each phrase as an algebraic expression. A. the quotient of a number and 4 quotient means “divide” B. w increased by 5 increased by means “add” w + 5 n4n4

Holt CA Course 1 1-6Writing Algebraic Expressions Example 1continued C. the difference of 3 times a number and 7 difference of means “subtract” D. the quotient of 4 and a number, increased by 10 3 x – 7 the quotient of 4 and a number, increased by 10 4n4n + 10 times means “multiply”

Holt CA Course 1 1-6Writing Algebraic Expressions Check It Out! Example 1 A. a number decreased by 10 decreased means “subtract” B. r plus 20 plus means “add” r + 20 n – 10 Write each phrase as an algebraic expression.

Holt CA Course 1 1-6Writing Algebraic Expressions When solving real-world problems, you may need to determine the action to know which operation to use. ActionOperation Put parts together Put equal parts together Find how much more Separate into equal parts Add Multiply Subtract Divide WRITE THESE IN THE BLANK SPACE

Holt CA Course 1 1-6Writing Algebraic Expressions Mr. Campbell drives at 55 mi/h. Write an algebraic expression for how far he can drive in h hours. Then evaluate the expression for h = 3, and tell what the value of the expression means. Example 2A: Translating Real-World Problems into Algebraic Expressions You need to put equal parts together. This involves multiplication. 55mi/h  h hours = Write the expression. Substitute 3 for h. 55  3 Multiply.165 Mr. Campbell can drive 165 miles in 3 hours if he drives at 55 miles per hour. 55(h)

Holt CA Course 1 1-6Writing Algebraic Expressions On a test, multiple-choice questions are worth 1 point, short-answer questions are worth 2 points, and essay questions are worth 10 points. Write an algebraic expression for Maritza’s total points if she answers m multiple-choice, s short-answer, and e essay questions correctly. Then evaluate the expression for m = 48, s = 8, and e = 3, and tell what the value of the expression means. Example 2B Multiply to put equal parts together. Points for multiple-choice questions: 1m or m Points for short-answer questions: 2s Points for essay questions: 10e

Holt CA Course 1 1-6Writing Algebraic Expressions Example 2B Continued Maritza earned 94 points on the test. Total points: 1m + 2s + 10eWrite the expression. Substitute 48 for m, 8 for s, and 3 for e. 1(48) + 2(8) + 10(3) Multiply from left to right Add.

Holt CA Course 1 1-6Writing Algebraic Expressions Check It Out! Example 1 1. Write each phrase as an algebraic expression. 4 times the difference of y and 8 y – 8 4 times the difference of y and 8 4(y – 8) 4

Holt CA Course 1 1-6Writing Algebraic Expressions You need to put equal parts together. This involves multiplication. 8(h) unitsWrite the expression. Substitute 5 for h.8(5) units Multiply.40 units Julie Ann can build 40 units in 5 hours. Check It Out! Example 2 Julie Ann works on an assembly line building computers. She can assemble 8 units an hour. Write an expression for the number of units she can produce in h hours. Then evaluate the expression for h = 5, and tell what the value of the expression means. 8 units/h  h hours = 8h

Holt CA Course 1 1-6Writing Algebraic Expressions For lunch, students have 3 choices. A turkey sandwich for $3, a bowl of soup for $2, and a chicken salad for $4. Write an algebraic expression to show how much it costs for s sandwiches, b bowls of soup, and c chicken salads. Then evaluate the expression for s = 32, b = 20, and c = 10, and tell what the value of the expression means. Check It Out! Example 2B Multiply to put equal parts together. turkey sandwich: 3s bowls of soup: 2bchicken salad: 4c

Holt CA Course 1 1-6Writing Algebraic Expressions Check It Out! Example 2B Continued Add to put equal parts together. The cost of 32 turkey sandwiches, 20 bowls of soup, and 10 chicken salads is $176. Total cost: 3s + 2b + 4c 3s + 2b + 4cWrite the expression. Substitute 32 for s, 20 for b, and 10 for c. 3(32) + 2(20) + 4(10) Multiply from left to right Add.