tìm x biết :-1/4<x<7/18

2 câu trả lời

Đáp án:

Ta có:

`MSC: 36`

`-1/4 = (-1.9)/(4.9) = -9/36`

`7/18 = (7.2)/(18.2) = 14/36`

`=> -9/36 < x < 14/36`

`=> x in {0;  ± 1/36 ; ±2/36 ; ±3/36; ±4/36 ; ±5/36 ; ±6/36 ; ±7/36 ; ±8/36 ; 9/36 ; 10/36 ; 11/36 ; 12/36 ; 13/36}`

Vậy ` x in{ -8/36 ; -7/36 ; ... ; 12/36 ; 13/36}`

`-1/4=-0.25`

`7/18≈0.389`

`=> x∈{-0.24; -0.23; -0.22; -0.21; -0.2; ....; 0.382; 0.383; 0.384; 0.385; 0.386; 0.387; 0.388}`

Với đk `-0.25<x<0.389` hay `-1/4<x<7/18`