Answer:
b,c,e
Step-by-step explanation:
You need the Law of Sines for this. In our case we have the measure of angle B and side b, we have the measure of angle A and are looking for side a, or x. Setting up the Law using our info, we have

. We will solve for x by multiplying both sides by sin(42):

, first choice above.
4x = 5x - 12
First you want to subtract 5x from both sides:
5x will cancel out
4x - 5 = -1
Next you want to divide -1 on both sides:
-1 will cancel out
-12/-1 = 12
Since there are two negatives it turns into a positive.
So your answer is x = 12.
Hope this Helps!!