Help please !!! I’m stuck on these problems

Answer:
[tex]b=6.8\ units[/tex]
Step-by-step explanation:
we know that
Applying the law of sines in the triangle ABC
[tex]\frac{AB}{sin(C)}=\frac{AC}{sin(B)}[/tex]
substitute the given values
[tex]\frac{15}{sin(140\°)}=\frac{b}{sin(17\°)}[/tex]
Solve for b
[tex]b=(sin(17\°))\frac{15}{sin(140\°)}[/tex]
[tex]b=6.8\ units[/tex]