Answer:
20 - 0.9u = 4.7
-0.9u = 4.7 - 20
-0.9u = -15.3
Divide both sides by - 0.9
u = 17
Hope this helps.
Answer: D
Step-by-step explanation:

Answer: 15.
Step-by-step explanation:
You divide the degrees by the side length. You get 15. So 15 is the answer.