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264                            C HAPTE R 3 I FRACTIONS



                   Definitions and Concepts                                      Examples
                         Section 3.6 Complex Fractions, Order of Operations, and Mixed Numbers


        A fraction whose numerator or denominator or both     Complex Fractions:
         contain fractions is called a complex fraction.
                                                                  11 1
                                                                        - 11
                                                                  4   6
                                                                    ,
                                                                  7     4
                                                                  10    3
        One method for simplifying complex fractions is to        1          1             1
         multiply the numerator and the denominator of the        6  - 11  6a 6  - 11b  6a b - 6(11)
                                                                                           6
         complex fraction by the LCD of all fractions in its        4    =      4     =       4
         numerator and its denominator.                                      6a b           6a b
                                                                    3           3             3
                                                                           1 - 66   -65      65
                                                                         =        =      =-
                                                                              8      8       8

        TO WRITE A MIXED NUMBER AS AN IMPROPER FRACTION           ƒ
                                                                        #
                                                                   2   7 5 + 2   35 + 2    37
         1. Multiply the denominator of the fraction by the whole  ƒ  5  =     =        =
           number.                                                7       7         7     7
         2. Add the numerator of the fraction to the product
           from Step 1.
         3. Write this sum from Step 2 as the numerator of the
           improper fraction over the original denominator.
        TO WRITE AN IMPROPER FRACTION AS A MIXED NUMBER
        OR A WHOLE NUMBER                                         17    2
                                                                     = 5
         1. Divide the denominator into the numerator.            3     3
         2. The whole number part of the mixed number is the
                                                                     5
           quotient.The fraction is the remainder over the
                                                                  317
           original denominator.
                                                                    15
                        remainder
           quotient                                                  2
                   original denominator
                                        Section 3.7 Operations on Mixed Numbers

                                                                                      #
        To multiply with mixed numbers or whole numbers, first          1 1   7 1    7 1    7
                                                                     2  #  =   #  =     =
         write any mixed or whole numbers as improper fractions        3 9   3 9    3 9    27
                                                                                      #
         and then multiply as usual.
                                                                                                   #
                                                                   5     7   21    55   21 16   21 16
        To divide with mixed numbers or whole numbers, first       2  , 3   =    ,     =   #   =
                                                                                                  #
                                                                   8    16    8    16   8  55    8 55
         write any mixed or whole numbers as fractions and then
                                                                                    1
                                                                                # #
         divide as usual.                                                    21 2  8    42
                                                                           =          =
                                                                                 #
                                                                                8  55   55
                                                                               1
                                                                      1    7
        To add or subtract with mixed numbers, add or subtract  Add:  2  + 5
                                                                      2    8
         the fractions and then add or subtract the whole
         numbers.                                                  1     4
                                                                 2   = 2
                                                                   2     8
                                                                   7     7                                          Copyright 2012 Pearson Education, Inc.
                                                                + 5  = 5
                                                                   8     8
                                                                        11        3     3
                                                                      7    = 7 + 1  = 8
                                                                        8         8     8
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