FOR THE STUDENT OF MATHEMATICS
DEMONSTRATION CLUB FILE XXI


PURPOSE: To demonstrate that for real number x, real number y and real number z:

                    XXI.     If x = y then x z = y z.

is true.



DEMONSTRATION:     STATEMENTS                                       REASONS



                            1.     x z = x z                     1.     Property XII   Reflexive:   p = p

                            2.     x = y                           2.     Given ( from the hypothesis or "If" part of the statement. )

                            3.     x z = y z                     3.     Property XVIII   Substitution of y for x



Multiplying the same quantity on both sides of an equality results in an equality.






Would you like to demonstrate Property XXII. ?

Properties:     List #1 Link     List #2 Link     List #3 Link     List #4 Link     List #5 Link   and   Demonstrations

Copyright © 2009 with all rights reserved by William V. Thayer         Assisted by Peter Rankin, Demo Club Member