solve x^3 + x^5 = [3 0;-1 5] where x is a matrix in matlab

main.m
x^3 + x^5 = [3 0;
             -1 5]
x^3(x^2 + I) = [3 0;
                -1 5]
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main.m
A = [3 0; -1 5];
B = A.^2 + eye(2); % calculate x^2 + I
C = B\A; % solve for x^3
x = nthroot(C, 3); % take the cube root of x^3 to get x
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main.m
x = [0.7372  0;
     0.1474  0.8640];
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