Solving for the Unknown
What we do to one side of the equation, we must do to the other side. This is the case, of course, because the two sides, by definition, are always equal.
states that two expressions or quantities are equal in value. The statement of equality 6
+ 4 = 19 is an equation that is algebraic shorthand for “the sum of 6 times a number plus 4 is equal to 19.” It can be seen that the equation 6
+ 4 = 19 is much easier to work with than the equivalent sentence.