I think you're having trouble because the equation you wrote for 8a has a slight typo.
The question says that the length is 9 less than twice the width. Your equation states the length is 9 times the width minus 2. So the length actually equals 2w – 9, meaning that w(2w – 9) = 180
Hope this helps! If you're still having trouble, let me know :)
Answer:

The file includes the input of your equation, comment if the equation you input is a mistake.
Answer:
A. 2/3
Step-by-step explanation:
Simplify it by four, 8 / 4 = 2, 12 / 4 = 3
6/12=X/18
Using the ratio of 18:12, you multiply 18/12 with 6, which equals 9.
Answer: NJ=9
Answer:
r≈5.64
Step-by-step explanation: