Determinant of a matrix can be defined as a numerical value obtained from a square matrix of the coefficients of certain unknown variables enclosed by two bars by the process of diagonal expansion to tell upon a given algebraic system.
Consider the system of equations:
a11x + a12y = 0 a12x + a22y = 0
Eliminating x and y, we get the expression as
a11a22 -a12a21 = 0