$\frac{x+8}{12}$ +$\frac{x+9}{11}$ +$\frac{x+10}{10}$

Đáp án:

Đề thiếu

Sửa đề `:` $\dfrac{x + 8}{12}$ `+` $\dfrac{x + 9}{11}$ `+` $\dfrac{x + 10}{10}$ `+` `3` `= 0`

`<=>` $\dfrac{x + 8 + 12}{12}$ `+` $\dfrac{x + 9 + 11}{11}$ `+` $\dfrac{x + 10 + 10}{10}$

`<=>` $\dfrac{x + 20}{12}$ `+` $\dfrac{x + 20}{11}$ `+` $\dfrac{x + 20}{10}$

`<=>` `(x + 20)(1/12 + 1/11 + 1/10) = 0`

`->` `x + 20 = 0`

`->` `x = -20`

Vậy `x = -20`

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`@Bi`