SOLUTION: Solve the system of linear equations -2x+4y-z =8 x+7y+2z=5 3x+3y+3z=-3 PLZ EXPLAIN IN STEPS

Algebra ->  Linear-equations -> SOLUTION: Solve the system of linear equations -2x+4y-z =8 x+7y+2z=5 3x+3y+3z=-3 PLZ EXPLAIN IN STEPS      Log On


   

Question 858239: Solve the system of linear equations
-2x+4y-z =8
x+7y+2z=5
3x+3y+3z=-3 PLZ EXPLAIN IN STEPS
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
-2 x + 4 y + -1 z = 8 --------------1
1 x + 7 y + 2 z = 5 --------------2
3 x + 3 y + 3 z = -3 --------------3

consider equation 1 &2 Eliminate y
Multiply 1 by -7
Multiply 2 by 4
we get
14 x + -28 y + 7 z = -56
4 x + 28 y + 8 z = 20
Add the two
18 x + 0 y + 15 z = -36 ------------- 4
consider equation 2 & 3 Eliminate y
Multiply 2 by -3
Multiply 3 by 7
we get
-3 x + -21 y + -6 z = -15
21 x + 21 y + 21 z = -21
Add the two
18 x + 15 z = -36 -------------5 5

the system has infinitely many or no solution