Đáp án:

 

Giải thích các bước giải:

* `1/3 . x + 2/5 .(x + 1) = 0`

`=> 1/3 . x + 2/5 . x + 2/5 = 0`

`=> 11/15 . x = -2/5`

`=> x = (-2/5) : 11/15`

`=> x = (-2/5) . 15/11 = -6/11`

Vậy `x = -6/11`

* `(1/4 . x - 1) - (5/6 . x + 2) - (1 - 5/8 . x) = 3`

`=> 1/4 . x - 1 - 5/6 . x - 2 - 1 + 5/8 . x = 3`

`=> (1/4 . x - 5/6 . x + 5/8 . x) + (-1 -2 -1)  = 3`

`=> 1/24 . x - 4 = 3`

`=> 1/24 . x = 7`

`=> x = 7 : 1/24 = 7 . 24 = 168`

Vậy `x = 168`

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Đáp án:

$\dfrac{1}{3}x+\dfrac{2}{5}(x-1)=0\Leftrightarrow x=\dfrac{6}{11}$

$\left ( \dfrac{1}{4}x-1 \right )-\left ( \dfrac{5}{6}x+2 \right )-\left ( 1-\dfrac{5}{8}x \right )=3\Leftrightarrow x=168$

Giải thích các bước giải:

$\dfrac{1}{3}x+\dfrac{2}{5}(x-1)=0\\\Leftrightarrow \dfrac{1}{3}x+\dfrac{2}{5}x-\dfrac{2}{5}=0\\\Leftrightarrow \dfrac{11}{15}-\dfrac{2}{5}=0\\\Leftrightarrow \dfrac{11}{15}x=\dfrac{2}{5}\\\Leftrightarrow x=\dfrac{6}{11}\\\left ( \dfrac{1}{4}x-1 \right )-\left ( \dfrac{5}{6}x+2 \right )-\left ( 1-\dfrac{5}{8}x \right )=3\\\Leftrightarrow \dfrac{1}{4}x-1-\dfrac{5}{6}x-2-1+\dfrac{5}{8}x=3\\\Leftrightarrow \left ( \dfrac{1}{4}x-\dfrac{5}{6}x+\dfrac{5}{8}x \right )+(-1-2-1)=3\\\Leftrightarrow \dfrac{1}{24}x-4=3\\\Leftrightarrow \dfrac{1}{24}x=7\\\Leftrightarrow x=168$