Using Carmer’s rule to solve for 7x-6y= 4, 4x-9y= -2

Let the first column to be [ 7 4 ] and second column to be [ -6 -9] and the constant column [4 -2]

det of the coefficient matrice A= -39

Since det of the coefficient matrice A is not equal to 0, the system has a unique solution:

x= (det of a 2x 2 matrice with the first column replaced by the constant column and the second column)/detA = -48/-39= 16/13

y =(det of a 2×2 matrice with the first column and the second column replaced by the constant column)/detA=-30/-39=10/13

http://www.purplemath.com/modules/cramers.htm

and maybe this one?

http://library.thinkquest.org/10030/10cramer.htm

http://en.wikipedia.org/wiki/Cramer’s_rule