What is the meaning of equality?

TMWYK: about solving for x


-Write a proportion
-Finding a missing # in an equation or proportion
-comp test, last problem
-You can break it down
-Do problem backwards
-Can use PEMDAS
-Guess and check
-  2 =   1
   4       2
-equal the same thing, have the same value
-2+4=3+3