Answer:

Step-by-step explanation:
You may have entered the measure of a side as the measure of an angle.





You are correct. Good job!
y = -1/2x + 5 should be your equation because it is 5 ft above sea level and its eroding, or going down, 1 ft per 20 years. So every year, the sand dune erodes 1/20 ft more.
Hope this helps!
14 2/3 This is the answer! I know you will get this right buddy!
4k(3n+2) this is basically just factoring out a common multiple which in this case is a k and a 4