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Question

6 tính tổng của tất cả các số nguyên x thỏa mãn

-9

-6

|x|<5

༄༂Nǧųƴễȵ ℋøàŋĢ Ţḧàṋħ ℕลм༉ツ · Accepted Answer

$-9\le x< 10$

$x=\left\{-9;-8;-7;...;7;8;9\right\}$

Tổng: $\left[\left(-9\right)+9\right]+\left[\left(-8\right)+8\right]+\left[\left(-7\right)+7\right]+...+\left[\left(-1\right)\right]+1$

$=0+0+0+...+0$

$=0$

$-6\le x< 5$

$x=\left\{-6;-5;-4;-3;...;3;4\right\}$

Tổng: $\left[\left(-4\right)+4\right]+\left[\left(-3\right)+3\right]+...+\left(-6\right)+\left(-5\right)$

$=0+0+\left(-6\right)+\left(-5\right)$

$=-11$

$\left| x\right|< 5$

$x=\left\{;-4;-3;...;3;4\right\}$

Tổng: $\left[\left(-4\right)+4\right]+\left[\left(-3\right)+3\right]+...+0$

$=0+0+...+0$

$=0$

Câu trả lời:

$-9\le x< 10$

$x=\left\{-9;-8;-7;...;7;8;9\right\}$

Tổng: $\left[\left(-9\right)+9\right]+\left[\left(-8\right)+8\right]+\left[\left(-7\right)+7\right]+...+\left[\left(-1\right)\right]+1$

$=0+0+0+...+0$

$=0$

$-6\le x< 5$

$x=\left\{-6;-5;-4;-3;...;3;4\right\}$

Tổng: $\left[\left(-4\right)+4\right]+\left[\left(-3\right)+3\right]+...+\left(-6\right)+\left(-5\right)$

$=0+0+\left(-6\right)+\left(-5\right)$

$=-11$

$\left| x\right|< 5$

$x=\left\{;-4;-3;...;3;4\right\}$

Tổng: $\left[\left(-4\right)+4\right]+\left[\left(-3\right)+3\right]+...+0$

$=0+0+...+0$

$=0$