EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the...

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EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and a number y c.The difference of 22 and the square of a number m 6n – 4 3(7 + y) 22 – m 2

Transcript of EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the...

Page 1: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

EXAMPLE 1 Translate verbal phrases into expressions

Verbal Phrase Expression

a. 4 less than the quantity 6 times a number n

b. 3 times the sum of 7 and a number y

c. The difference of 22 and the square of a number m

6n – 4

3(7 + y)

22 – m2

Page 2: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

GUIDED PRACTICE for Example 1

1. Translate the phrase “the quotient when the quantity 10 plus a number x is divided by 2” into an expression.

ANSWER

1. Expression 10 + x2

Page 3: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

SOLUTION

Cutting A Ribbon

EXAMPLE 2 Write an expression

A piece of ribbon l feet long is cut from a ribbon 8 feet long. Write an expression for the length (in feet) of the remaining piece.

Draw a diagram and use a specific case to help you write the expression.Suppose the piece cut is 2 feet long.

Suppose the piece cut is L feet long.

The remaining piece is(8 – 2) feet long.

The remaining piece is(8 – l) feet long.

Page 4: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

EXAMPLE 2 Write an expression

ANSWER

The expression 8 – l represents the length (in feet) of the remaining piece.

Page 5: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

Write a verbal model.

SOLUTION

You work with 5 other people at an ice cream stand. All the workers put their tips into a jar and share the amount in the jar equally at the end of the day. Write an expression for each person’s share (in dollars) of the tips.

Tips

EXAMPLE 3 Use a verbal model to write an expression

Translate the verbal model into an algebraic expression. Let a represent the amount (in dollars) in the jar.

STEP 1

STEP 2Amount

in jarNumber

of people

a 6

Page 6: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

EXAMPLE 3 Use a verbal model to write an expression

ANSWER

An expression that represents each person’s share (in dollars) is .a

6

Page 7: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

GUIDED PRACTICE for Examples 2 and 3

WHAT IF? In Example 2, suppose that you cut the original ribbon into p pieces of equal length. Write an expression that represents the length (in feet) of each piece.

ANSWER

lp

Page 8: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

GUIDED PRACTICE for Examples 2 and 3

WHAT IF? In Example 3, suppose that each of the 6 workers contributes an equal amount for an after-work celebration. Write an expression that represents the total amount (in dollars) contributed.

ANSWER

6d, where d represents the amount contributed by each worker.

Page 9: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

EXAMPLE 4 Find a unit rate

A car travels 110 miles in 2 hours. Find the unit rate.

110 miles 2 hours = 1 hour

55 miles2 hours 2

110 miles 2 =

The unit rate is 55 miles per hour, or 55 mi/h.

ANSWER

Page 10: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

SOLUTION

EXAMPLE 5 Solve a multi-step problem

Cell PhonesYour basic monthly charge for cell phone service is $30, which includes 300 free minutes. You pay a fee for each extra minute you use. One month you paid $3.75 for 15 extra minutes. Find your total bill if you use 22 extra minutes.

STEP 1 Calculate the unit rate.

153.75

= 0.25 1 = $.25 per minute

Page 11: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

EXAMPLE 5 Solve a multi-step problem

Write a verbal model and then an expression. Let m be the number of extra minutes.

Use unit analysis to check that the expression 30 + 0.25m is reasonable.

minutedollarsdollars + minutes = dollars + dollars = dollars

Because the units are dollars, the expression is reasonable.

STEP 2

30 + 0.25 m

Page 12: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

EXAMPLE 5 Solve a multi-step problem

Evaluate the expression when m = 22.

30 + 0.25(22) = 35.5

ANSWER

The total bill is $35.50.

STEP 3

Page 13: EXAMPLE 1 Translate verbal phrases into expressions Verbal Phrase Expression a. 4 less than the quantity 6 times a number n b. 3 times the sum of 7 and.

EXAMPLE 5 Solve a multi-step problem

Evaluate the expression when m = 22.

30 + 0.25(22) = 35.5

ANSWER

The total bill is $35.50.

STEP 3