Question 328163
1.{{{x-y+z=-4}}}
2.{{{x+2y-z=-2}}}
3.{{{x+y-4z=1}}}
Subtract eq. 1 from eq. 2,
{{{x+2y-z-x+y-z=-2-(-4)}}}
4.{{{3y-2z=2}}}
Subtract eq. 1 from eq. 3,
{{{x+y-4z-x+y-z=1-(-4)}}}
5.{{{2y-5z=5}}}
Mutliply eq. 4 by 2 and eq. 5 by -3 to eliminate y,
{{{6y-4z-6y+15z=4-15}}}
{{{11z=-11}}}
{{{highlight( z=-1)}}}
Then use either eq.4 or eq. 5 to solve for y.
{{{3y+2=2}}}
{{{3y=0}}}
{{{highlight( y=0)}}}
Finally use 1,2,3 to solve for x.
{{{x+0+(-1)=-4}}}
{{{highlight( x=-3)}}}