Question 173523
adding 1st eqn and 2nd eqn __ 4x+y=1


subtracting 4x __ y=1-4x


adding 1st eqn and 3rd eqn __ -x+2y=11


substituting __ -x+2(1-4x)=11


distributing __ -x+2-8x=11


subtracting 2 __ -9x=9


dividing by -9 __ x=-1


substituting __ y=1-4(-1) __ y=5


substituting __ (-1)-(5)+z=-4


adding 6 __ z=2