SOLUTION: Solve each system using Gaussian elimination. State whether each system is independent, inconsistent, or dependent.

Algebra.Com
Question 44742This question is from textbook College Algebra
: Solve each system using Gaussian elimination. State whether each system is independent, inconsistent, or dependent. This question is from textbook College Algebra

Found 2 solutions by Nazareth, venugopalramana:
Answer by Nazareth(2)   (Show Source): You can put this solution on YOUR website!
Elimination Method
3x - 6y = 9.....multiply this line by 2
2x + y = -4.....mutiply by 3
We have:
6x - 12y = 18...(1)
6x + 3y = -12...(2)
we work by eliminating x therefore (1) - (2)
We have:
6x - 6x = 0
-12y -3y = -15y
and 18 - (-12)= 30
This give -15y = 30
Divide both side by -15, we have:
y = -2
Replcing the value of y in any of the above equation:
for example
we use
3x -6y=9
3x - 6(-2) = 9
3x +12 = 9, since - x - = +
then take away 12 from both sides, leaving
3x = - 3
giving x = -1
Answer:
x = -1
y = -2

Answer by venugopalramana(3286)   (Show Source): You can put this solution on YOUR website!
SEE THE FOLLOWING EXAMPLE AND TRY.COME BACK IF STILL IN DIFFICULTY
--------------------------------------------------------------------------------
x - y + z = 2
-x + y + z = 4
-x + z = 2
augmented matrix is
1.....................-1.......................1.............................2
-1.....................1.......................1.............................4
-1.....................0.......................1.............................2
nr2=r2+r1 and nr3=r3+r1
1..................-1.................1.............2
1-1=0............1-1=0............1+1=2..........2+4=6
1-1=0...........-1+0=-1...........1+1=2..........2+2=4
nr2=r2/2....nr3=r3-r2
1....................-1...............1..............2
0/2=0.............0/2=0..............2/2=1........6/2=3
0-0=0............-1-0=-1..............2-2=0.......4-6=-2
nr1=r1-r3-r2.......nr2=2r2........nr3=-r3
1-0-0=1............-1+1-0=0.........1-0-1=0.......2+2-3=1
0.....................0...................1............3
0.....................1...................0.............2
exchange r2 and r3
1....0........0.......1
0....1........0.......2
0....0........1.......3
hence x=1......y=2.....z=3

RELATED QUESTIONS

Solve each system using Gaussian elimination. State whether each system is independent,... (answered by venugopalramana)
Solve each system using Gaussian elimination. State whether each system is independent,... (answered by venugopalramana)
Solve each system in three variables using Gaussian elimination. State whether each... (answered by venugopalramana)
Solve each system by substitution. Determine whether each system is independent,... (answered by AnlytcPhil)
Solve each system by substitution. Determine whether each system is independent,... (answered by AnlytcPhil)
Solve each system by substitution. Determine whether each system is independent,... (answered by fractalier)
Solve each system by substitution. Determine whether each system is independent,... (answered by fractalier)
Solve each system by substitution. Determine whether each system is independent,... (answered by fractalier)
Solve each system by substitution. Determine whether each system is independent,... (answered by venugopalramana)