First, perform any operations possible within groupings.
Next you could use distributive property, IF YOU WANT TO, or could choose to
use a lattice method for multiplication.
6x -2y Y
------------------------
2x | 12x^2 -4xy 2xY
|
3y | 18xy -6y^2 3yY
Combine like-terms using addition.
-------or other variations based on commutative property for addition.