Solving Matrix of Differential Equations With Initial Values

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Homework Statement


Solve the matrix of differential equations with given initial values.

dx/dt= (-6 2) x
(-3 -1)

Initial value is x(0) = -2
-5

Homework Equations



(A-λI)=o


The Attempt at a Solution



My eigenvalues are -4 and 3

My eigenvectors for -4 are 1 and 1 and the eigenvectors for -3 are 1 on the top row and 3/2 on the bottom.

I write out the equations to look like:

C1e^-4t + C2e^-3t
C1e^-4t + 3/2C2e^-3t

I have IVs of -2 on the top row and -5 on the bottom row. To plug these in correctly,do I use the top row values for the top row equation and same for the bottom? If so, I'm getting C1=4 and C2=-6 but this is wrong in our online homework program.
 
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I figured out what I was doing wrong. It was a matter of entering the answer into the online homework program incorrectly, not so much that the answers were wrong.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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