Basic Mathematics for College Students

WRITING

95. Explain how to find the LCM of 8 and 28 using
    prime factorization.


96. Explain how to find the GCF of 8 and 28 using
    prime factorization.


97. The prime factorization of 12 is and the
    prime factorization of 15 is Explain why the
    LCM of 12 and 15 is not


98. How can you tell by looking at the prime
    factorizations of two whole numbers that their
    GCF is 1?

REVIEW

Perform each operation.

99. 
    
    
    
    100. 
         
    
    
    
    


100. 305  50 102.2,100 105

9,9991,111 10,0007,989

2  2  3  3 5.

3 5.

2  2  3

1.9 Order of Operations 101

93. ART CLASSES Students in a painting class must
    pay an extra art supplies fee. On the first day of class,
    the instructor collected $28 in fees from several
    students. On the second day she collected $21 more
    from some different students, and on the third day
    she collected an additional $63 from other students.
    a. What is the most the art supplies fee could cost a
    student?
    a. Determine how many students paid the art
    supplies fee each day.


94. SHIPPING A toy manufacturer needs to ship
    135 brown teddy bears, 105 black teddy bears, and
    30 white teddy bears. They can pack only one type of
    teddy bear in each box, and they must pack the same
    number of teddy bears in each box. What is the
    greatest number of teddy bears they can pack in each
    box?

Recall that numbers are combined with the operations of addition, subtraction,
multiplication, and division to create expressions.We often have to evaluate(find
the value of) expressions that involve more than one operation. In this section, we
introduce an order-of-operations rule to follow in such cases.

SECTION 1.9

Order of Operations

Objectives

1 Use the order of operations rule.

2 Evaluate expressions containing

grouping symbols.

3 Find the mean (average) of a set

of values.

1 Use the order of operations rule.

Suppose you are asked to contact a friend if you see a Rolex watch for sale while
you are traveling in Europe. While in Switzerland, you find the watch and send the
following text message, shown on the left. The next day, you get the response shown
on the right from your friend.

You sent this

message.

You get this

response.