Expert: Abe Mantell - 6/7/2006

Question
Help!  I need Intermediate Algebra help.  I would appreciate any help you can provide.  I have worked these problems for not just hours but days.  Diana

Cramer's Rule to solve for x,y,z:
-2x-3y+7z=19
-3x+3y-8z=-56
-7x-5y+4z=-44

Find an equation in standard form:
(-2,-6) and (2,-3)

Find x,y,z

3x + 14y + 4z = 113
2x + 3y + 16z = 97
8x + 4y +7z = 120

Find x,y,z

x + y + z = 374
10x + 9y + 8.5z = 3551
11.5 + 10y + 9.5z = 4038  

Answer
Hello Diana,

Check these links for how to use Cramer's Rule...it is tough for me to type all that and make it look nice!
http://www.purplemath.com/modules/cramers.htm
http://library.thinkquest.org/10030/10cramer.htm
http://distance-ed.math.tamu.edu/Math640/chapter1/node9.html
http://www.sosmath.com/matrix/determ2/determ2.html

You should get the following answers:
1. x=6, y=6, z=7
2. the equation of a line in standard form is: Ax+By=C
-- certainly you must know how to find the slope of a
-- line...then use it to get y=mx+b...yes?  Then get it
-- in the form Ax+By=C...you should get: 3x-4y=18
3. x=9, y=5, z=4
4. x=226, y=66, z=82