Page 180 - Basic College Mathematics with Early Integers
P. 180

GROUP ACTIVITY                          157

            Evaluate.


                      4                                                     6
            117. 1-122                                            118. 1-172


                       2
                                                                         2
                  3
            119. x - y  for x  = 21 and y =-19                    120. 3x + 2x - y for x =-18 and y = 2868
                         x
                                                                                b
            121. 1xy + z2  for x = 2, y =-5, and z = 7            122. 51ab + 32 for a =-2, b = 3





                    Chapter 2 Group Activity

              Magic Squares                                       Exercises
              Sections 2.2–2.4                                    1. Verify that what is shown in the Dürer engraving is, in
                                                                    fact, a magic square. What is the common sum of the
              A magic square is a set of numbers arranged in a square
                                                                    columns, rows, and diagonals?
              table so that the sum of the numbers in each column,
              row, and diagonal is the same. For instance, in the magic  2. Negative numbers can also be used in magic squares.
              square below, the sum of each column, row, and diagonal  Complete the following magic square:
              is 15. Notice that no number is used more than once in
              the magic square.


                                 2    9    4                                             -1

                                 7    5    3                                        0         -4

                                 6    1    8


                                                                  3. Use the numbers -16, -12, -8, -4,  0, 4, 8, 12, and 16
                 The properties of magic squares have been known
                                                                    to form a magic square:
              for a very long time and once were thought to be good
              luck charms. The ancient Egyptians and Greeks under-
              stood their patterns. A magic square even made it into a
              famous work of art. The engraving titled Melencolia I,
              created by German artist Albrecht Dürer in 1514, fea-
              tures the following four-by-four magic square on the
              building behind the central figure.



                              16    3    2   13
                               5   10   11    8


                               9    6    7   12

                               4   15   14    1
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