Page 19 - Math Course 2 (Book 1)
P. 19

Using the Distributive Property






                              Let’s Begin                        Simplify 6x + 4 – 5x – 7.
                                                                 6x and –5x are like terms. 4 and –7 are also like
                                                                 terms.

                                                                 6x + 4 – 5x – 7  = 6x + 4 + (–5x) + (–7)
                Identify Parts of Expressions                                          Def nition of subtraction

                                                                                = 6x + (–5x) + 4 + (–7)
                 Example                                                               Commutative Property
                                                                                = [6 + (–5)]x + 4 + (–7)
                 Identify the terms, like terms, coef  cients, and                     Distributive Property
                 constants in the expression 4x – x + 2y – 3.
                                                                                = x –3  Simplify
                 4x – x + 2y – 3 = 4x + (–x) + 2y + (–3)
                                      Def nition of subtraction.
                                                                     Answer       x – 3
                                     = 4x + (–1x) + 2y + (–3)
                                      Identity Property.

                                The terms are 4x, –x, 2y, and –3.   Simplify –y + 2(x + 3y).
                               The like terms are 4x and –x. The
                    Answer
                                coef  cients are 4, –1, and 2. The   –y + 2(x + 3y) = –y + 2x + 2(3y)  Distributive Property
                                       constant is –3.
                                                                                   = –y + 2x + 6y   Associative Property

                                                                                   = –1y + 6y + 2x   Commutative
                                                                                              Property
                Simplify Algebraic Expressions
                                                                                   = (–1 + 6)y + 2x   Distributive Property
                 Example                                                           = 5y + 2x    Simplify



                 Simplify 8n + 4 + 4n.                               Answer       5y + 2x
                 8n and 4n are like terms.

                 8n + 4 + 4n = 8n + 4n + 4    Commutative
                                              Property           Real World Example

                                = (8 + 4)n + 4   Distributive     WORK
                                              Property
                                                                  You and a friend worked in the school store last
                                                                  week. You worked 4 hours more than your friend.
                              = 12n + 4       Simplify.
                                                                  Write an expression in simplest form that represents
                                                                  the total number of hours you both worked.
                    Answer       12n + 4                             Words     number of hours your friend worked

                                                                               + number of hours you worked

                                                                    Variables  Let h = number of hours your friend
                                                                               worked.
                                                                               Let h + 4 = number of hours you
                                                                               worked.


                                                                   Expression h + h + 4





                                                                                                                  11
   14   15   16   17   18   19   20   21   22   23   24