Question

x= +5 ; y= -6 ; z=-2

Answer 1

Somando-se os termos :

2X + Y + Z + W = 1
X + 2Y + Z + W = 2
X + Y + 2Z + W = 3
X + Y + Z + 2W = 4
_______________________
5X +5Y + 5Z +5 W = 10

Então para simplificar nosso trabalho fiz :

 = X + Y + Z + W = 2

Então eu fui montando sistemas:

1- 

2X + Y + Z + W = 1 
X + Y + Z + W = 2 .(-1) 

2X + Y + Z + W = 1
-X - Y - Z - W =- 2 
_______________
X= -1

2-

X + 2Y + Z + W = 2
X + Y + Z + W = 2 .(-1)

X + 2Y + Z + W = 2
-X - Y - Z - W =- 2 
___________________
Y = 0

3-
X + Y + 2Z + W = 3
X + Y + Z + W = 2 .(-1)

X + Y + 2Z + W = 3
-X - Y - Z - W =- 2 
__________________
Z = 1

4-
X + Y + Z + 2W = 4
X + Y + Z + W = 2 .(-1)

X + Y + Z + 2W = 4
-X - Y - Z - W =- 2 
__________________
W = 2 

R: X = -1 / Y = 0 / W = 2 / Z = 1

Answer 2

x-y+2z=-1

y=x+2z+1

 

2x+z=0

z=-2x 

 

x+5y+z=5

x=5-5y-z 

 

z=-2(5-5y-z)

z=-10+10y+2z 

z+10=10y+2z

10=10y+z

z=10-10y

 

x=5-5y-(10-10y)

x=5-5y-10+10y

x=5y-5

 

y=5y-5+2(10-10y)+1

y=5y-5+20-20y+1

 

x=0

y=1

z=0

 

y=-15y+16

16y=16

y=1

 

z=10-10y

z=10-10

z=0

 

x=5y-5

x=5-5

x=0