i need help with pre-cal, please!

Answer:
b ≈ 4.2
Step-by-step explanation:
Using the tangent ratio in the right triangle, that is
tan50° = [tex]\frac{opposite}{adjacent}[/tex] = [tex]\frac{BC}{AC}[/tex] = [tex]\frac{5}{b}[/tex] ( multiply both sides by b )
b × tan50° = 5 ( divide both sides by tan50° )
b = [tex]\frac{5}{tan50}[/tex] ≈ 4.2 ( to the nearest tenth )