Question

HELPPPPP MEEE PLZZZZ!!!

Answer 1

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 $\frac{x}{sin(42)} = \frac{9}{sin(29)}$.  We will solve for x by multiplying both sides by sin(42): $x= \frac{9sin(42)}{sin(29)}$, first choice above.