You can take (x - 2y) out of all three of those terms, leaving 3a, 4b and c.
Well, darling, "6ay" doesn't really mean anything in the English language. It seems like someone might have made a typo or a funky keyboard slip. If you're trying to crack a secret code, I'm afraid this one might just be gibberish. Keep on sleuthing, detective!
The expression (-6ay) represents the product of -6, the variable (a), and the variable (y). It indicates that the value is negative and depends on the values of (a) and (y). If (a) and (y) are both positive, the overall expression will be negative. Conversely, if either (a) or (y) is negative, the expression will be positive.