Giải thích các bước giải:
`a)`
`13/19 - 3/8 < x - 1/5 < 11/15 + 2/3`
`=> 47/152 < x - 1/5 < 7/5`
`=> 47/152 + 1/5 < x < 7/5 + 1/5`
`=> 387/760 < x < 8/5`
`=> 0,5 < x < 1,6`
`=> x in {0,6; 0,7; 0,8; ...; 1,5; 1,6}`
$\\$
`b)`
`1/3 +2/7 < 0.5 - 2/3x < 3/4 + 0,25`
`=>13/21 < 0.5 - 2/3x < 1`
`=>13/21 - 0.5 < -2/3x < 1 - 0,5`
`=>5/42 < -2/3x < 1/2`
`=>5/42 : -2/3< x < 1/2 : -2/3`
`=>-5/28 < x < -3/4`
`=>-0,18 < x < -0,75`
`=> x = -0,1`