SOLUTION: Solve by writing a matrix equation and solving with the inverse matrix. -4x-3y-z=-36 x+7y-9z=-68 8x+y+z=58

Algebra ->  Matrices-and-determiminant -> SOLUTION: Solve by writing a matrix equation and solving with the inverse matrix. -4x-3y-z=-36 x+7y-9z=-68 8x+y+z=58      Log On


   

Question 1134300: Solve by writing a matrix equation and solving with the inverse matrix.
-4x-3y-z=-36
x+7y-9z=-68
8x+y+z=58
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

-4x+-+3y+-+z+=+-36
x+%2B+7y+-+9z+=+-68
8x+%2B+y+%2B+z+=+58

Rewrite the system in matrix form and solve it by Gaussian Elimination (Gauss-Jordan elimination)




divide the 1 row by -4



multiply 1 row by 1 and subtract it from 2 row, and multiply 1 row by 8+and subtract it from 3 row



divide the 2 row by+6.25




multiply 2 row by 0.75 and subtract it from 1 row, and multiply 2 row by 5 and add it to 3 row





divide the 3 row by -8.4




multiply 3 row by 1.36 and subtract it from 1 row, and multiply 3+row by 1.48+and add it to+2 row




solutions:
x+=+6
y+=+1
z=+9