Câu 1 A)0,5 . ^100 – 1/4 . ^16 + (-2/3)2² B)5/17 + 2/3 – 20/12 + 7/9 + 12/17 Câu 2 A) 3/2x + 1/4 = 5/2 B) 2 2/3 : x = 1 1/2 : 0,02 Bạn nhớ trả

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1. Câu `1` :

   `a)` 

   `0,5 . \sqrt{100} – 1/4 . \sqrt{16} + (-2/3) . 2^2`

   `= 0,5 . 10 – 1/4 . 4 + (-2/3) . 4`

   `= 5 – 1 + (-8)/3`

   `= 4 + (-8)/3`

   `= 12/3 – 8/3`

   `= 4/3`

   `b)`

   `5/17 + 2/3 – 20/12 + 7/9 + 12/17`

   `= (5/17+12/17) + (2/3 + 7/9 – 20/12 )`

   `= 1 + (  24/36 + 28/36 – 60/36 )`

   `= 1 – 8/36`

   `= 36/36 – 8/36`

   `= 28/36`

   `= 7/9` 

   Câu `2` :

   `a)`

   `3/2 x + 1/4 = 5/2`

   `=> 3/2 x = 10/4 – 1/4`

   `=> 3/2 x = 9/4`

   `=> x = 9/4 . 2/3`

   `=> x = 3/2`

   `b)`

   `2  2/3 : x = 1 1/2 : 0,02`

   `8/3 : x = 3/2 : 0,02`

   `8/3 : x = 1,5 : 0,02`

   `8/3 : x = 75`

   `x = 8/3 . 1/75`

   `x = 8/225`

    

   Trả lời

2. Đáp án:

   `↓↓↓`

   Giải thích các bước giải:

   Câu 1

   `a) 0,5 . \sqrt{100}  -1/4 . \sqrt{16} + (-2/3) . 2^2`

   `= 0,5 . 10 – 1/4 . 4 + (-2/3) . 4`

   `= 5 – 4 . (1/4 + (-2)/3)`

   `= 5 – 4 . (-5)/12`

   `= 5 – (-5)/3`

   `= 20/3`

   `b) 5/17 + 2/3 – 20/12 + 7/9 + 12/17`

   `= (5/12 + 12/17) + 2/3 – 20/12 + 7/9`

   `= 1 + 2/3 – 20/12 + 7/9`

   `= 5/3 – 20/12 + 7/9`

   `= 0 + 7/9`

   `= 7/9`

   Câu 2

   `a) 3/2x + 1/4 = 5/2`

   `-> 3/2x = 9/4`

   `-> x = 3/2`

   `b) 2 2/3 : x = 1 1/2 : 0,02`

   `-> 8/3 : x = 3/2 : 0,02`

   `-> 8/3 : x = 75`

   `-> x = 8/225`

    

   Trả lời