SOLUTION: solve the system of equtaions by gauss-elimination method x+y+z=9 x-2y+3z=8 2x+y-z=3

Algebra ->  Matrices-and-determiminant -> SOLUTION: solve the system of equtaions by gauss-elimination method x+y+z=9 x-2y+3z=8 2x+y-z=3       Log On


   

Question 250951: solve the system of equtaions by gauss-elimination method
x+y+z=9
x-2y+3z=8
2x+y-z=3






Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Add 1 and 3,
x%2By%2Bz%2B2x%2By-z=9%2B3+
4.3x%2B2y=12
Multiply 3 by 3 and add to 2,
6x%2B3y-3z%2Bx-2y%2B3z=9%2B8
5.7x%2By=17
Multiply 5 by -2 and add to 4.
-14x-2y%2B3x%2B2y=-34%2B12
-11x=-22
x=2
Now work backwards,
7x%2By=17
14%2By=17
y=3
.
.
x%2By%2Bz=9
2%2B3%2Bz=9
z=4
.
.
.
(x,y,z)=(2,3,4)