Question

The following expression represents the value of which variable in the solution of the system of equations below?
|2 -1 1|
|1 2 6|
|3 -1 2|
___________
|2 -1 -2|
|1 2 3|
|3 -1 -1|

2X-Y+Z=-2
X+2Y+6Z=3
3X-Y+2Z=-1

A. Z
B. Y
C. X
D. NONE OF THE VARIABLES ARE REPRESENTED

Answer 1

You replace the third column in the NUMERATOR determinant with the right hand side, NOT THE DENOMINATOR to get the third variable, Z. Therefore you got 1/Z

Answer 2

Here is a link to Cramer's rule:
http://www.purplemath.com/modules/cramers.htm