Simple math problem could indicate your religious beliefs.

[Tiberius]

Can't we just start at the bold equation since the question doesn't care how much the bat costs. It is just asking what x is when x + (x + 100) = 110.

Sure, you can do that, but some people might be a bit confused as to how you got that equation in the first place. With linear equations, the standard way to solve them is to write out all the details of the question as simple equations first, and then combine them, cancelling out variables as you go.