3+2+1=-12
2-3+4=23
3+2+1 (3. -3 .1) + (2.2) + (2.4)+(3. -3 .1) + (2.2) +(2.4) = -18+24=6
buscamos X -12 +2 +1
23 -3 +4
-12 +2 +1 (-12. -3 .1) + (23.2) + (2.4)(23.2) + (-12. -3 .1)+ (2.4)=
36+46+8+46+36+8=180
buscamos Y 3 -12 1
2 23 4
3 -12 1 (3.23.1)+ (-12.4)+(2. -12)+(2. -12) + (3.23.1) +(-12.4)=
69-48-24-24+69-48=-6
buscamos Z por sustitución
3X + 2Y +Z = -12
3.180 + 2. -1 + z = -12
540 -2 + z = -12
Z= -538-12
Z= -550
comprobación 3.180 +2 . -1 -550 = -12
540 - 2 - 550 = -12 -552 + 540=-12 -12 = -12
