# Thread: Use Cramer's rule to find x2

1. ## Use Cramer's rule to find x2

Compute the cofactors $\displaystyle C_{12}, C_{22}, C_{32}$ for the matrix A =
[ 1 2 3 ]
[ 2 1 3 ]
[ 1 -1 1]. Use the cremar's rule to find x_2 when Ax = [1 -2 1]^T

I got the $\displaystyle C_{12} = -5, C_{22} = -4 , C_{32} = -3$, how do I find $\displaystyle x_2$?

2. This same problem was posted and answered at http://www.mathhelpforum.com/math-he...2-when-ax.html