How to convert a symbolic matrix into matrix polynomial

I have a matrix with its elements as polynomials, such as the following N matrix. I was wondering whether it would be possible to convert it into a matrix polynomial expression like N0 + N1*x + N2*x^2? My idea is to retrieve the matrices N0, N1, N2. I would deeply appreciate any pointers regarding this. Thank you.

syms x
N = [1 5-3*x 0;0 1 5-3*x;1 0 x^2-5];

[Walter Roberson]

Is x intended to be scalar or matrix itself?

[Isaac]

x is a symbolic variable. So it is indeed a scalar.

Answer 1

[VBBV]

syms x
N = [1 5-3*x 0;0 1 5-3*x;1 0 x^2-5]

N = 

K = poly2sym(N,[x])

K = 

simplify(K)

ans = 

[VBBV]

use poly2sym for converting to symbolic polynomial expressions

[Isaac]

Thank you for the reply, I suppose I have poorely worded my question. My intention was to decompse the N matrix into the following N0, N1, N2 matrices, such that N = N0 + N1*x + N2*x^2;

N0 = [1 5 0;0 1 5;1 0 -5]; N1 = [0 -3 0;0 0 -3;0 0 0]; N2 = [0 0 0;0 0 0;0 0 1];