Question

1,{2x+y+z=-26,x+2y+z=-30,x+y+2z=-28 2,{5x+2y+z=12,4x+3y+z=13

Answer 1

1,﹛2x+y+z=-26,x+2y+z=-30,x+y+2z=-28,4x+4y+4z=-84,x+y+z=-21,﹛x=-5,y=-9,z=-7,2,﹛5x+2y+z=12,4x+3y+z=13,3x-4y+5z=10,﹛x-y=-1,22x+14y=50,﹛x=1,y=2,z=3,