Instead of doing yours for you, I'll do one exactly
like it, so you can use it as a model and learn to
do this kind of problem by yourself:

x+y+z = 6
2x-y+z = 3
x+2y-3z = -4

First put in all the 1, -1, and 0 coefficients, if
necessary:



Cramer's rule:
 
There are 4 columns,
 
1. The column of x-coefficients 
 
2. The column of y-coefficients 
 
3. The column of z-coefficients  
 
4. The column of constants:     

I colored the column of constants red because that is
the column that "moves" from left to right in the 
determinants.
 
There are four determinants:
 
1. The determinant  consists of just the three columns
of x, y, and z coefficients. in that order, but does not
contain the column of constants.
 
. 
 
It has value .  I'm assuming you know how to find the
value of a 3x3 determinant, for that's a subject all by itself.
If you don't know how, ask me in the thank-you note form below
this problem.  I don't charge any money.  I do this for fun! 
 
2. The determinant  is like the determinant 
except that the column of x-coefficients is replaced by the
column of constants.   does not contain the column 
of x-coefficients.
 
.
 
It has value .
 
3. The determinant  is like the determinant 
except that the column of y-coefficients is replaced by the
column of constants.   does not contain the column 
of y-coefficients.
 
.
 
It has value .
 
4. The determinant  is like the determinant 
except that the column of z-coefficients is replaced by the
column of constants.   does not contain the column 
of z-coefficients.
 
.
 
It has value .
 
Now the formulas for x, y and z are
 




Now do the same with yours.  

[Hint as a check: Two of the values of your solution are
the same as two of the values in the problem I worked above.] 

Edwin