How to find the dominant eigenvalue of A

I tried doing the diag. 3 times and adding them but my answer was 7.8336e+04 instead of what the question says I'm supposed to get in order to proceed, any thoughts?

[David Goodmanson]

Hi Paul, an obvious first thought would be, how does the A you constructed compare with the A given in the problem?

[Peter Chang]

Hi Paul, the problem you attached is principally the same with this one. My suggestion: First, make sure the Matrix A you created is correct. If yes, you will get the right value of det(A). Sec., generally, the dominant eigenvalues of a Matrix is the ones with the largest absolute values. To find it, you can e.g. use the command eig.