MATLAB: Please i want to solve linear equations which takes the form of AX=B where x is the unknown variables but i have another unknown in row 2 of matrix B how i can not solve this problem

iterative linear equation

matrix
A=[2-j*3   -0.9+j*9   0        0       0    -1+j*19;
         -0.9+j*9   2-j*3   j*9       0       0   -1+j*9;
          0         j*9     17-j*3   -17+j*2  0     0;
          0         0       -17+j*2   17-j*4  j*2   0;
          0         0       0         j*2     -j*25 0;
          -1+j*19   -1+j*19 0         0        0    3-j*39;      ];
B=[5;y;0;0;2;0]; % y is the unknown variable
X=[x1;x2;x3;x4;x5;x6]
i want to find the values of matrix x and the value of y
how i can solve these lonear equations

Best Answer

You have 6 equations in 7 unknowns. You do not have enough information to determine all of the variables x1, x2, x3, x4, x5, x6, and y .
syms y x1 x2 x3 x4 x5 x6
A=[2-j*3   -0.9+j*9   0        0       0    -1+j*19;
       -0.9+j*9   2-j*3   j*9       0       0   -1+j*9;
        0         j*9     17-j*3   -17+j*2  0     0;
        0         0       -17+j*2   17-j*4  j*2   0;
        0         0       0         j*2     -j*25 0;
        -1+j*19   -1+j*19 0         0        0    3-j*39;      ];
B=[5;y;0;0;2;0]; % y is the unknown variable
X=[x1;x2;x3;x4;x5;x6];
sol = solve(A*X == B, X)
This will have sol.x1 through sol.x6, all dependent on the variable y. If you knew any one x* value then you could calculate y. For example,
Y = solve(sol.x1 == 3+4*j, y)
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