Bài 2 (1,5 điểm): Tìm x biết: a) x + $\frac{2}{5}$ = $\frac{-4}{3}$ b) $\frac{-5}{6}$ + $\frac{1}{3}$.x = ($\frac{-1}{2}$)² c) $\frac{7}{12}$ - (x + $\frac{7}{6}$).$\frac{6}{5}$ = ($\frac{-1}{2}$)³

`a . ` `x+2/5=(-4)/3`

`=>` `x=(-4)/3-2/5`

`=>` `x=-14/15`

Vậy `x=-14/15`

`- - - - - - - - - -`

`b . ` `(-5)/6+1/3*x=((-1)/2)^2`

`=>` `(-5)/6+1/3*x=1/4`

`=>` `1/3*x=1/4-((-5)/6)`

`=>` `1/3*x=6/24-((-20)/24)`

`=>` `1/3*x=(6-(-20))/24`

`=>` `1/3*x=26/24`

`=>` `x=26/24:1/3`

`=>` `x=26/24*3/1`

`=>` `x=78/24`

`=>` `x=13/4`

Vậy `x=13/4`

`- - - - - - - - - -`

`c . ` `7/12-(x+7/6)*6/5=((-1)/2)^3`

`=>` `7/12-(x+7/6)*6/5=(-1/8)`

`=>` `(x+7/6)*6/5=7/12-(-1/8)`

`=>` `(x+7/6)*6/5=56/96-(-12/96)`

`=>` `(x+7/6)*6/5=(56-(-12))/96`

`=>` `(x+7/6)*6/5=68/96`

`=>` `(x+7/6)=68/96:6/5`

`=>` `(x+7/6)=68/96*5/6`

`=>` `(x+7/6)=340/576`

`=>` `x+7/6=340/576`

`=>` `x=340/576-7/6`

`=>` `x=-83/144`

Vậy `x=-83/144`

`#me`