Beginning Algebra, 11th Edition

(Marvins-Underground-K-12) #1

NOTE The problem in Example 2could also be solved by letting xrepresent the


number of medals the United States won. Then would represent the number


of medals Sweden won. The equation would be different.


The solution of this equation is 25, which is the number of U.S. medals. The number


of Swedish medals would be The answers are the same,whichever


approach is used, even though the equation and its solution are different.


Finding the Number of Orders for Tea

The owner of Terry’s Coffeehouse found that on one day the number of orders for tea


was the number of orders for coffee. If the total number of orders for the two drinks


was 76, how many orders were placed for tea?


Step 1 Readthe problem. It asks for the number of orders for tea.


Step 2 Assign a variable.Because of the way the problem is stated, let the variable


represent the number of orders for coffee.


Let the number of orders for coffee.


Then the number of orders for tea.


Step 3 Write an equation.Use the fact that the total number of orders was 76.


The orders for orders
total is coffee plus for tea.

76 x


Step 4 Solve.


Multiply by

57 =x


3

4.


3


4


1762 =


3


4


a


4


3


xb


76 =


4


3


x


1


3


= + x


13 x=


x=


1
3

EXAMPLE 3

25 - 11 =14.


39 =x+ 1 x- 112


x- 11


110 CHAPTER 2 Linear Equations and Inequalities in One Variable


NOW TRY
EXERCISE 3
In one week, the owner of
Carly’s Coffeehouse found
that the number of orders for
bagels was the number of
orders for chocolate scones.
If the total number of orders
for the two items was 525,
how many orders were placed
for bagels?


2
3

Be careful!
This is not
the answer.

In Example 3,it was easier to let the variable represent the quantity that was


notspecified. This required extra work in Step 5 to find the number of orders


for tea. In some cases, this approach is easier than letting the variable represent


the quantity that we are asked to find.


PROBLEM-SOLVING HINT

Combine like terms.

x= 1 x=^33 x ;

Step 5 State the answer.In this problem, x does not represent the quantity that we


are asked to find.The number of orders for tea was So is


the number of orders for tea.


Step 6 Check.The number of orders for tea, 19, is one-third the number of orders


for coffee, 57, and Since this agrees with the information


given in the problem, the answer is correct. NOW TRY


19 + 57 =76.


1

3 1572 =^19


1

3 x.


NOW TRY ANSWER



  1. 210 bagel orders


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