Which expression shows \( 3 x-7 y-12 y \) properly combined?

The expression \( 3x - 7y - 12y \) can be simplified by combining the like terms \( -7y \) and \( -12y \). When you add these together, you get \( -19y \). Therefore, the properly combined expression is \( 3x - 19y \). This simplification illustrates the fantastic world of algebra where we can re-organize and condense expressions for clearer understanding. Just like cleaning your room, tidying up your equations makes it easier to see what you've got! If you are tackling polynomial expressions, practicing combining like terms will make you a pro in no time. A tip is to always group similar variables together to avoid confusion. Remember, mistaking \( -19y \) for \( -5y \) is a common mistake when you're just starting out!