Question

X+y=12x-y+z=1x+2y+z=8/3x=y=z=

Answer 1

x+y=1 (a)

2x-y+z=1 (b)

x+2y+z=8/3 (c)

Eliminate 1 variable:

subtract b to c:

x+2y+z=8/3 (c)

-

2x-y+z=1 (b)

_________

-x+3y = 5/3 (1)

(a) and (1)

x+y=1

-x+3y= 5/3

Add both_

x+y=1

+

-x+3y= 5/3

_________

4y=8/3

y= (8/3 )/4

y= 2/3

Replace y on (a)

x+2/3=1

x=1-2/3

x= 1/3

Replace x and y on b

2x-y+z=1

2(1/3)-2/3+z=1

2/3-2/3 +z=1

z=1