To combine a pair of inequalities, there must be a common term, much like common denominators in fractions. Since x is the only variable that appears in both inequalities, let's turn that into a common term: 6x. To convert y > -3x into something that contains 6x, multiply both sides by 2. Remember that, when multiplying an inequality by a negative, you must reverse the sign:
-2y < 6x
To get a 6x in the second inequality, multiply both sides by 3:
-3z > 6x
Now arrange the terms from smallest to largers, as they are arranged in each of the choices:
-2y < 6x < -3z, choice (A).