To find this answer, we subtract each of the like terms in the equation. 3x and 3x are like terms, -4y and 2y are like terms, and 7 and -5 are like terms. Now we subtract. 3x - 3x is 0, -4y - 2y is -6y, and 7 - (-5) is 12. That means that the result is -6y = 12, or B.