How to solve Ax=0.. with 4 unknowns and 4 linear equations I am trying to solve 4 linear equations for a 3D triangulation problem to create a function in matlab code.
I have 4 equations such as
aX + bY + cZ + dW = 0
eX + fY + gZ + hW = 0
iX + jY + kZ + lW = 0
mX + nY + oZ + pW = 0
Here, I have to solve for X, Y, Z and W
I am totally new to linear algebra and solving systems linear equations. Please guide me on how to solve this to obtain the 4 unknowns.
Thanks in advance for your valuable time...

The question was tagged (matlab), so I will provide an appropriate solution.
% construct the matrix
A = [a,b,c,d;
     e,f,g,h;
     i,j,k,l;
     m,n,o,p];

% the solution will be in the nullspace of the matrix A
Z = null(A);

The vectors in the columns of Z form a basis for $\mathcal{N}(A)$, so that the solution to the linear system can be written as $\mathbf{x}=Z\mathbf{c}$, where $\mathbf{c}$ is a column vector with the same number of rows as the columns of $Z$.
This approach is not efficient when $A$ is a large matrix, as the function null computes the singular value decomposition of the matrix. This approach will work when $A$ is both singular and non-singular.
