Solve symbolic Sylvester-like equation

I'm looking for a way to solve a symbolic Sylvester-like equation in MATLAB or MAPLE (or any other available tool). In particular, I have the following equation,

where, A has some parameters in it (like below). B is known and I want to solve for X as a function of a.

Answer 1

[Torsten]

syms a x11 x12 x21 x22 b11 b12 b21 b22
A=[a+sym('1'), sym('2'); sym('3'),sym('1')];
X=[x11,x12;x21,x22];
B=[b11,b12;b21,b22];
[solx11 solx12 solx21 solx22] = solve([A*X+X*A==B],[x11 x12 x21 x22])

[madhan ravi]

A = sym([a + x, 1; 3, 1]);

[Torsten]

What is x ?

Why A12 = 1 instead of 2 ?

[madhan ravi]

Ah (typo) , meant to say sym() can be used directly for the whole matrix instead of applying to each values of a matrix.