Đáp án:
Giải thích các bước giải:
$a:5x<15$
$=>5x.\dfrac{1}{5}<15.\dfrac{1}{5}$
$=>x<3$
$b:-6x>-18$
$=>-6x.\dfrac{1}{6}>-18.\dfrac{1}{6}$
$=>-x>-3$
$=>x<3$
$c:0,5x>-2$
$=>0,5x.2>-2.2$
$=>x>-4$
$d: -0,8x<32$
$=>-0,8x.\dfrac{5}{4}<32.\dfrac{5}{4}$
$=>-x<40$
$=>x>40$
`e:3/4x>2`
`=>3/4x. 4/3>2. 4/3`
`=>x>16/9`
`f:4/5x<4`
`=>4/5x. 5/4>4. 5/4`
`=>x>5`