Question 147218
See this --> http://library.thinkquest.org/2647/algebra/post.htm

Then substitute in 'numbers' or other combinations of letters to create examples.

For instance:
Transitive Property of Equality: if a = b and b = c, then a = c
example If 12 = (9+3)   and (9+3) = (13-1)  then 12 = (13-1)  OR
if x = y     and y = 2z   then x = 2z