Question 639160
{{{system(2x - y - 3z = -1, 2x - y + z = -9,x + 2y - 4z = 17)}}}
Multiply the third equation by 2
{{{system(2x - y - 3z = -1, 2x - y + z = -9,2x + 4y - 8z = 34)}}}
Subtract the first equation from the second and from the third equations
{{{system(2x - y - 3z = -1, 4z = -8, 5y - 5z = 35)}}}
From the second equation{{{z=-2}}}
Substitute {{{z=-2}}} into the third equation
{{{5y+10=35}}}
{{{5y=25}}}
{{{y=5}}}
Substitute {{{z=-2, y=5}}} into the first equation
{{{2x-5+6=-1}}}
{{{2x=-2}}}
{{{x=-1}}}
Answer: {{{system(x=-1, y=5, z=-2)}}}