Answer
$x^{o} \approx 50.8^{o} $
Work Step by Step
Apply law of cosines $n^2=m^2+p^2-2 mp \cos N$
Need to solve for n.
That is, $n=\sqrt {m^2+p^2-2 mp \cos N} $
Plug the given values to obtain:
$a=\sqrt {(30)^2+(38)^2-2 \times 30 \times 38 \cos 50^{o}} \approx 29.6$
In order to calculate the value of $B$, we will use $M =x^{o}$.
$\dfrac{\sin M}{m}=\dfrac{\sin N}{n} \implies M=\sin^{-1} (\dfrac{m \sin N}{n}) $
or, $x^{o}=\sin^{-1} (\dfrac{30 \sin 50^{o}}{29.6}) \implies x^{o} \approx 50.8^{o} $
