Bài 2: Thực hiện phép tính A) 5.2² - 18:3 B) 17.85+15.17-2³.3.5 C) 2³.17-2³.14 D) 20-[30-(5-1)²]

Answer

`a, 5 . 2^2 - 18 : 3`

`= 5 . 4 - 6`

`= 20 - 6`

`= 14`

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`b, 17 . 85 + 15 . 17 - 2^3 . 3 . 5`

`= 17 . (85 + 15) - 8 . 3 . 5`

`= 17 . 100 - 24 . 5`

`= 1700 - 120`

`= 1580`

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`c, 2^3 . 17 - 2^3 . 14`

`= 8 . 17 - 8 . 14`

`= 8 . (17 - 14)`

`= 8 . 3`

`= 24`

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`d, 20 - [30 - (5 - 1)^2]`

`= 20 - [30 - 4^2]`

`= 20 - [30 - 16]`

`= 20 - 14`

`= 6`