Question

solve this system by matrices
2x+3y-z=-8
x-y-z=-2
-4x+3y+z=6

Answer 1

Jessica, it would be quite cumbersome to attempt typing matrices in this format.

Do you know how to find the inverse of a matrix?
Find it then multiply it by the column vector
-8
-2
6

Answer 2

here is one method to find the inverse

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

Personally I use a method using adjoints, which seems very easy to do once you do it a few times.
On the other hand it is not easy to explain.

Here is a page where they try, but the first part might seem confusing.
They also form the adjoint at the end, I form it as my first step

http://www.easycalculation.com/matrix/inverse-matrix-tutorial.php