Question 255688
I need help solving this problem using the Cramer's rule to find the value of "z" that satisfies the system of linear equations. 
Here is the link to my question:
http://s699.photobucket.com/albums/vv356/flowerpatch_01/?action=view¤t=Picture4-10.png 
So far I have D= 4,-5, 1
2, 5, -2
-2, 3, -4 
Thanks so much in advance for your help!
<pre><font size = 4 color = "indigo"><b>
That photobucket site does not come up on my computer, so
I just made up the numbers on the right, colored red.
You can change them to the right numbers:

I'll assume your system of equations was this:

{{{system(4x-5y+z=red(6),2x+5y-2z=red(3),-2x+3y-4z=red(7))}}}

{{{D=abs(matrix(3,3,
4,-5, 1,
2, 5, -2,
-2, 3, -4))}}} 

x is the FIRST unknown and so {{{D[x]}}} is just like {{{D}}}
except that the FIRST column is replaced by the three red numbers,
which I made up: 

{{{D[x]=abs(matrix(3,3,
red(6),-5, 1,
red(3), 5, -2,
red(7), 3, -4))}}}

y is the SECOND unknown and so {{{D[y]}}} is just like {{{D}}}
except that the SECOND column is replaced by the three red numbers,
which I made up: 


{{{D[y]=abs(matrix(3,3,
4,red(6), 1,
2, red(3), -2,
-2, red(7), -4))}}}

z is the THIRD unknown and so {{{D[z]}}} is just like {{{D}}}
except that the THIRD column is replaced by the three red numbers,
which I made up: 

{{{D[z]=abs(matrix(3,3,
4,-5, red(6),
2, 5, red(3),
-2, 3, red(7)))}}}

Do you know how to evaluate a 3x3 determinant?
If not, post again asking how to.  I will assume
you already know how.

{{{D=-100}}}
{{{D[x]=-100}}}
{{{D[y]=100}}}
{{{D[z]=300}}}

Then the solutions are:

{{{x=D[x]/D=(-100)/100 = -1}}}
{{{y=D[y]/D=(100)/100 = 1}}}
{{{z=D[z]/D=(300)/100 = 3}}}

Now substitute your numbers for the red numbers
and evaluate the determinants and you'll have your 
solution.

Edwin</pre>