Giải giúp mik dc ko ạ :

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`b,`

`|x+2| + |5/2 - y|=0`

Vì `|x+2| ≥0∀x, |5/2 - y| ≥0∀y`

`-> |x+2|+|5/2 - y| ≥0∀x,y`

Dấu "`=`" xảy ra khi :

`|x+2|=0, |5/2 - y|=0`

`↔x+2=0, 5/2 - y=0`

`↔x=-2,y=5/2`

Vậy `(x;y)=(-2;5/2)`

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Bài `4.`

`a,`

`|x-0,5| + |y+ 1 1/2| + |3/4 -z|=0`

`-> |x-1/2| + |y + 3/2| + |3/4-z|=0`

Vì `|x-1/2| ≥0∀x, |y+3/2| ≥0∀y, |3/4 - z| ≥0∀z`

`-> |x-1/2| + |y + 3/2| + |3/4-z| ≥0∀x,y,z`

Dấu "`=`" xảy ra khi :

`|x-1/2|=0, |y+3/2|=0, |3/4-z|=0`

`↔ x-1/2 =0, y+3/2=0, 3/4 -z=0`

`↔x=1/2, y=(-3)/2, z=3/4`

Vậy `(x;y;z)=(1/2; (-3)/2; 3/4)`

`b,`

`|2x-2| + |3y+1/2| + |6-3z|=0`

Vì `|2x-2| ≥0∀x, |3y+1/2| ≥0∀y, |6-3z| ≥0∀z`

`-> |2x-2| + |3y+1/2| + |6-3z| ≥0∀x,y,z`

Dấu "`=`" xảy ra khi :

`|2x-2|=0, |3y+1/2|=0, |6-3z|=0`

`↔ 2x-2=0, 3y+1/2=0,6-3z=0`

`↔2x=2, 3y=(-1)/2, 3z=6`

`↔x=1, y=(-1)/6, z=2`

Vậy `(x;y;z)=(1;(-1)/6; 2)`