Question 356680
1.{{{2x - 12y + 3z = -19}}}
2.{{{4x + 6y - 2z = 14}}}
3.{{{6x - 9y - 4z = 13}}}
From eq. 1,
{{{2x=12y-3z-19}}}
Multiply by (2),
{{{4x=24y-6z-38}}}
Multiply by (3),
{{{6x=36y-9z-57}}}
Now substitute into eq. 2 and eq. 3,
{{{(24y-6z-38)+6y-2z=14}}}
{{{30y-8z=52}}}
4.{{{15y-4z=26}}}
.
.
{{{(36y-9z-57)- 9y - 4z = 13}}}
5.{{{27y-13z=70}}}
From eq. 4,
{{{4z=15y-26}}}
{{{z=(15/4)y-13/2}}}
Substitute into eq. 5,
{{{27y-13((15/4)z-13/2)=70}}}
{{{108y-13(15z-26)=280}}}
{{{108y-195y+338=280}}}
{{{-87y+338=280}}}
{{{-87y=-58}}}
{{{y=58/87}}}
{{{highlight(y=2/3)}}}
Then,
{{{z=(15/4)(2/3)-13/2}}}
{{{z=5/2-13/2}}}
{{{z=-8/2}}}
{{{highlight(z=-4)}}}
Then,
{{{2x=12(2/3)-3(-4)-19}}}
{{{2x=8+12-19}}}
{{{2x=1}}}
{{{highlight(x=1/2)}}}