Page 29 - Math Course 1 (Book 2)
P. 29

Solving Open Sentence Equations





                                                                   Your Turn!
                                                     True or
                  a            4a + 7 = 23
                                                     False?       Use a Replacement Set to Solve an Equation
                  2       4(2) + 7 ≟ 23 → 15 ≠ 23     false
                  3       4(3) + 7 ≟ 23 → 19 ≠ 23     false       A. Find the solution set for 6c – 5 = 7 if the
                  4      4(4) + 7  ≟ 23 → 23 = 23     true !           replacement set is {0, 1, 2, 3, 4}.
                  5      4(5) + 7  ≟ 23 → 27 ≠ 23     false        A.  {0}
                  6      4(6) + 7  ≟ 23 → 31 ≠ 23     false        B.  {2}
                                                                   C.  {1}
                                                                   D.  {4}
                    Answer          The solution set is {4}.

                                                                     Answer

                Find the solution set for 3(8 – b) = 6 if the replace-
                ment set is {2, 3, 4, 5, 6}.

                Replace b in 3(8 – b) = 6 with each value in the    B. Find the solution set for 4(h – 2) = –8 if the
                replacement set.
                                                                        replacement set is {0, 1, 2, 3, 4}.
                                                     True or
                  a            3(8 – b) = 6                        A.  {1}
                                                     False?
                                                                   B.  {2}
                  2        3(8 – 2) ≟ 6 → 18 ≠ 6      false        C.  {0}
                  3        3(8 – 3) ≟ 6 → 15 ≠ 6      false        D.  {3}
                  4        3(8 – 4) ≟ 6 → 12 ≠ 6      false
                  5        3(8 – 5) ≟ 6 → 9 ≠ 6       false          Answer
                  6        3(8 – 6) ≟ 6 → 6 = 6       true !


                    Answer         The solution set is {6}.



               Use Order of Operations to Solve an Equation       Use Order of Operations to Solve an Equation
                                                                           3(6 + 4)  = w
                                                                  Solve
                  Examples                                               21 – (10–6) 2


                        5(8 + 2)                                   A.  1
                 Solve            = k
                      18 – (5 – 3) 3                                  30
                                                                   B.
                   5(8 + 2)                                           37
                                                                      3
                 18 – (5 – 3) 3  = k  Original equation            C.   8

                    5(10)           Add 8 and 2 in the             D.  6
                  18 – (2) 3  = k   numerator. Subtract 5
                                    and 3 in the denominator
                    5(10)
                    18 – 8   = k    Evaluate the power in the
                                    denominator.
                     50      = k
                     10             Simplify
                                                                     Answer
                                        5 = k  Divide.
                    Answer
                                      The solution is 5.



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