**Quote:**

Would like to know a better way than plugging examples. Because there might be a possibility that the examples I plug in may/may not suit the situation and the answer we are looking at.

First of all, note that there is the algebraic solution provided in the last part of the explanation.

Secondly, plugging in few

*easy* numbers is a good method that will help to eliminate wrong answers and/or understand a problem better. You may use it if you don't see an algebraic solution. If you eliminate all answer choices except one, then that one is the right answer.

When you plug in numbers, do not pick them all at once, but replace variables one-by-one, trying to fit the new value with the already chosen ones.