what is the solution to this 3 by 3 system of equations
2x-y-z=0
x-2z=1
x+y-5z=3
2x - y - z = 0 (1)
x -2z = 1 ⇒ x = 1 + 2z (2)
x + y -5z = 3 (3)
Sub (2) into (1) and (3) for x and we have that
2 (1 + 2z) - y - z = 0 ⇒ -y + 3z = -2 ( 4)
(1 + 2z) + y -5z = 3 ⇒ y - 3z = 2 (5)
If we add (4) and (5) we get that 0 = 0
This means that we have infinite solutions here for x,y and z
Using (5) we have that y = 2 + 3z
So....holding z constant we have that
(x , y , z) = ( 1 + 2z , 2 + 3z , z )