Given 4x+2y+z=7 (a)

2x+2y-4z= -8 (b)

x+3y-2z= -8 (c)

Eq (b) can be simplified by dividing it with 2 and get x+y-2z=-4. Subtract this one from Eq(c)

x+3y-2z= -8

x+y-2z=-4

- - + +

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0+2y+0 =-4

Or y= -2

Substituting for y, Eq (a) becomes 4x+z= 11 and

Eq (b) becomes 2x-4z= -4.

Subtract twice of the Eq 2x-4z=-4 from 4x+z=11. This gives z= 19/9 and hence x= 20/9

The required solution is x= 20/9, y=-2 and z= 19/9 Answer