The given system of equations, in augmented matrix form can be written as follows

 

 

Now carry out Row operations R2= R2-R1 and R3=R3-3R1

 

.

 

Next R3= R3+4R2 will yield  , which is now in Reduced Row Echelon Form.   From R3 we have z= -1

             From R2 we have y+3z=-5,  giving us y=-2

             From R1 we have x+y-z=0, giving us  x=  1

 

Hence Solution is (x,y,z)= (1,-2,-1)