Addition and Subtraction of Expressions that Include Variables

Adding and subtracting expressions in math with unknown variables is like combining groups of things or taking away groups of things.
Let's say you have two expressions with unknown variables. An expression is like a little math sentence with numbers and letters. When you add or subtract these expressions, you want to put similar terms together.
The goal is to group similar terms together and perform the operations on the numbers in front of the variables while keeping the variables the same.

[awesome]

To all the people asking “what’s the value of b?”, well we don’t have a full equation. I.e. we don’t know what -2b+2 equals. The whole point of this exercise is to simplify the equation from a big clunky one to a small and simpler one.

[fearlessjoebanzai]

How is negative 2b plus 2 the "final answer"? The final answer should be the answer of that equation.

[Steven]

If thats the final answer that he living is b!???