Question

X-y+5z=3 4x+z=0 x+3y+z=-9

Answer 1

x - y + 5z = 3   ....  (1)

4x + z = 0         .......(2)

x + 3y + z = -9  .......(3)

From (2) z = -4x,   Substitute for  z in (1) and (3):-

x - y + 5(-4x) = 3

-19x + y = 3 ......(4)

x + 3y - 4x = -9

-3x + 3y = -9

- x + y = -3  .....(5)

Subtract:-  (4) - (5) we get

-18x = 0

x = 0

So z = -4x = 0

Substituting for x and z in equation (3):-

3y = -9

y = -3

Answer is x = 0 , y = -3 and z = 0