Answer:
a)

Therefore letter B is the correct answer.
b) TP = 23.7 yards
Explanation:
a) We can rewrite
as (b-x)(b-x), so we have a product of two binomials. We can use the FOIL method to multiply it:

so the the Law of Cosines equation will be write as:

Therefore letter B is the correct answer.
b) Here we can use the Law of sines.
- TP is the distance between Tyrone and the piano
- DP is the distance between Diego and the piano
- TD is the distance between Diego and Tyrone.
∠A angle between TD and TP = 65°
∠B angle between TD and DP = 77°
∠C angle between TP and DP = 180° - 77° - 65° = 38°
The equation is:

Solving it for TP, we have:
I hope it helps you!