Multiple choice What must be added to 3x + y to get 2x + 3y 5x + 4y -x + 2y X -2y X + 2y Reveal answer Fill a bubble to check yourself B Correct answer Explanation Let the required expression be X. Then 3x + y + X = 2x + 3y, so X = 2x + 3y - 3x - y = -x + 2y. This gives us what must be added to transform the first expression into the second.