Question

use inverse matrix method to determine x,y and z of......
3x+3y+3z=4
x-y-z=0
20x+0+z=5

Answer 1

If AX = B then X = A^-1 B
A^-1 =
(1/6 1/2 0)
(7/2 19/2 -1)
(-10/3 -10 1)

So, X = (2/3 9 -25/3)^{^T}