SOLUTION: x+y+z=6 2x-y+z=3 x+2y-3z=-4 solve using cramers rule

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Question 355223: x+y+z=6
2x-y+z=3
x+2y-3z=-4
solve using cramers rule

Found 2 solutions by Alan3354, Edwin McCravy:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
x+y+z=6
2x-y+z=3
x+2y-3z=-4
------------
You can check your answers.
x = 1
y = 2
z = 3

Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
x+y+z=6
2x-y+z=3
x+2y-3z=-4
solve using cramers rule



Write in all the 1 and -1 coefficients:



Cramer's rule:
 
There are 4 columns,
 
1. The column of x-coefficients matrix%283%2C1%2C1%2C2%2C1%29
 
2. The column of y-coefficients matrix%283%2C1%2C1%2C-1%2C2%29
 
3. The column of z-coefficients matrix%283%2C1%2C1%2C1%2C-3%29 
 
4. The column of constants:     red%28matrix%283%2C1%2C6%2C3%2C-4%29%29
 
There are four determinants:
 
1. The determinant D consists of just the three columns
of x, y, and z coefficients. in that order, but does not
contain the column of constants.
 
D=abs%28matrix%283%2C3%2C1%2C1%2C1%2C2%2C-1%2C1%2C1%2C2%2C-3%29%29. 
 
It has value D=13.  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, post again asking how. 
 
2. The determinant D%5Bx%5D is like the determinant D
except that the column of x-coefficients is replaced by the
column of constants.  D%5Bx%5D does not contain the column 
of x-coefficients.
 
.
 
It has value D%5Bx%5D=13.
 
3. The determinant D%5By%5D is like the determinant D
except that the column of y-coefficients is replaced by the
column of constants.  D%5By%5D does not contain the column 
of y-coefficients.
 
.
 
It has value D%5By%5D=26.
 
4. The determinant D%5Bz%5D is like the determinant D
except that the column of z-coefficients is replaced by the
column of constants.  D%5Bz%5D does not contain the column 
of z-coefficients.
 
.
 
It has value D%5Bx%5D=39.
 
Now the formulas for x, y and z are
 
x=D%5Bx%5D%2FD=13%2F13=1
y=D%5By%5D%2FD=26%2F13=2
x=D%5Bz%5D%2FD=39%2F13=3
 
Edwin