Cramer's rule is a method of solving simultaneous equations
for unknowns.
Any system of equations of this kind can be written
in the form
(1)
The coefficients on the left side of Eq.'s 1 can be
written as a matrix,
(2)
The value of any of the can be found via
(3)
where the notation and denote the
determinants
of matrices and , and the matrix is obtained by
replacing the column of matrix with the coefficients on
the left side of Eq.'s 1. For example,