Question

b) X+y+2 z=28
x+2 y+z=20
2x+ y+z=10​

Answer 1

Explicação passo-a-passo:

z=20-x-2y

y=10-2x-z= 10-2x-20-x-2y=> y=(-10-3x)/3

y=(-10/3)-x

z=20-x-2((-10-3x)/3)=20-x-(-20/3)-(-2x)

z=20+(20/3)+x=(60+20+3x)/3=x+(80/3)

x+y+2z=28

x+(-10/3)-x+2(x+(80/3))=28

2x+((80-10)/3)=28

6x+70= 28*3

x= (84-70)/6=14/6

y=-10/3 - 14/6 = -20/6 -14/6= -34/6=-17/3

z=14/6+80/3=7/3+80/3=87/3