A set of m linear equations in n unknowns x1, x2,…, xn that has the form
Here, unlike the non-homogeneous case, the numbers on the right-hand sides of the equations are all zero. In matrix notation, this set of equations can be written Ax=0, where the unknowns form a column matrix x. Thus A is the m×n matrix [aij], andIf x is a solution of a homogeneous set of linear equations, then so is any scalar multiple kx of it. There is always the trivial solution x=0. What is generally of concern is whether it has other solutions besides this one. For a homogeneous set consisting of the same number of equations as unknowns, the matrix of coefficients A is a square matrix, and the set of equations has non-trivial solutions if and only if detA=0.