Calculus Problem: Boat propeller/matrix/derivatives

[ITF]

Here's the problem, attached to the post. I've tried using matrices to solve it but I'm not sure if the answers I am getting are correct. The professor hinted that the answers should be whole numbers, but I keep getting decimals. Any help??

I've uploaded a scan of my work, scan02 is where I plugged in for the X's and found the derivatives. I then put them into a matrix.

Thanks,
ITF

 

[ITF]

Here's the problem, attached to the post. I've tried using matrices to solve it but I'm not sure if the answers I am getting are correct. The professor hinted that the answers should be whole numbers, but I keep getting decimals. Any help??

I've uploaded a scan of my work, scan02 is where I plugged in for the X's and found the derivatives. I then put them into a matrix.

Thanks,
ITF

Sorry, I have to reply in order to attach my matrix working. The limit is three files. Anyhoo, my work isn't exactly the "prettiest" but at least I hope it's clean enough for a Helper to show me where I went wrong. It also shows the answers I got for each variable, (A, B, C, D,..etc.)

Thanks again!
ITF