Gấp ạaaaaaaaaa. Làm hết cho e với ạaaa

`a`

`|x - 1| + |y - 2| + |-1/3| = |2/9| - |-2/3| + (9/7)^(-1)`

`|x - 1| + |y - 2| + 1/3 = 2/9 - 2/3 + 7/9`

`|x - 1| + |y - 2| + 1/3 = 1/3`

`|x - 1| + |y - 2| = 0`

Vì `|x - 1| >= 0, |y - 2| >= 0 AA x, y`

`to {(x - 1 = 0),(y - 2 = 0):}`

`to {(x = 1),(y = 2):}`

Vậy` x = 1, y = 2`

`b`

`|x + y + z - 1/200| + |y + 2z| = -|x| - |y - 1/100|`

`to |x + y + z - 1/200| + |y + 2z| + |x| + |y - 1/100| = 0`

Vì `|x + y + z - 1/200| >=0 AA x;y;z `

`|y+2z | >=0 ; | x| >=0 ; |y-1/100| >=0 AA x;y;z`

`to {(x = 0),(y - 1/100 = 0),(y + 2z = 0),(x + y + z - 1/200 = 0):}`

`to {(x=0),(y=1/100),(z=-y/2):}`

`to {(x=0),(y=1/100),(z=-1/200),(x+y+z=-1/200 (tm)):}`

Vậy `x = 0, y = 1/100, z = -1/200`