Bài 2: (1,5 điểm) Tìm x, biết: a) x - $\frac{2}{5}$ = $\frac{-9}{10}$ b) $\frac{3}{4}$ + $\frac{1}{4}$x = $\frac{-5}{6}$ c) |x + $\frac{1}{2}$| - $\frac{1}{3}$ = 0

`Accnswer`

`a)x-2/4=-9/10`

`=>x=-9/10+2/5`

`=>x=(-9+4)/10`

`=>x=-1/2`

Vậy `x=-1/2`

`b)3/4+1/4x=-5/6`

`=>1/4x=-5/6-3/4`

`=>1/4x=-19/12`

`=>x=-19/12:1/4`

`=>x=-19/3`

Vậy `x=-19/3`

`c)|x+1/2|-1/3=0`

`=>|x+1/2|=1/3`

`@TH_1:`

`x+1/2=1/3`

`=>x=1/3-1/2`

`=>x=-1/6`

`@TH_2:` `x+1/2=-1/3`

`=>x=-1/3-1/2`

`=>x=-5/6`

Vậy `x in{-1/6;-5/6}`