SOLUTION: -2x+y-6z=-114 12x+6y=132 x+z=12 not sure how to do this- do you put 0 for those that don't have three? I am supposed to do this with Cramer's Rule. need to find the value of

Yes, you write it lined up this way:

-2x +  y - 6z = -114
12x + 6y      =  132
  x +       z =   12

Then you put in some 1's, 0z and 0y:

-2x + 1y - 6z = -114
12x + 6y + 0z =  132
 1x + 0y + 1z =   12

I'll assume you know how to find the value of a determinant.

You make the denominator determinant by using the coefficients of the
letters:



Notice that the numerator determinants are just like D except for the
column I've made red, which are the numbers right of the equal signs 
replaces one column and notice how it "moves" from left to right: 







, , 

Edwin