Câu hỏi của Mai Hương

Question

Tính: $-21,3\cdot15,4+8,3\cdot4,6-21,3\cdot4,6+8,3\cdot15,4$

Giúp mk vs

Đời về cơ bản là buồn...... · Accepted Answer

$-21,3\cdot15,4+8,3\cdot4,6-21,3\cdot4,6+8,3\cdot15,4$

$=\left(-21,3\cdot15,4-21,3\cdot4,6\right)+\left(8,3\cdot4,6+8,3\cdot15,4\right)$

$=-21,3\cdot\left(15,4+4,6\right)+8,3\left(4,6+15,4\right)$

$=20\cdot\left(8,3-21,3\right)$

$=-13\cdot20$

$=-260$Câu trả lời: $-21,3\cdot15,4+8,3\cdot4,6-21,3\cdot4,6+8,3\cdot15,4$

$=\left(-21,3\cdot15,4-21,3\cdot4,6\right)+\left(8,3\cdot4,6+8,3\cdot15,4\right)$

$=-21,3\cdot\left(15,4+4,6\right)+8,3\left(4,6+15,4\right)$

$=20\cdot\left(8,3-21,3\right)$

$=-13\cdot20$

$=-260$

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