Đáp án + Giải thích các bước giải:

`a)` `5871 : [928-(247-82)\times5].`

`= 5871 : [ 928 - 825].`

`= 5871 : [ 928 - ( 247-82)\times5].`

`= 5871 : 103.`

`= 57.`

`b)` `33\times75+25.33-280.`

`= 33\times(75+25)-280.`

`= 33. 75 + 25.33 - 280 = 33 . 100 - 280.`

`= 33\times75+25\times33-280`

`= 3300 - 280.`

`= 3020.`

`c)` `98\times31 + 98\times24 + 98\times27 + 2\times82.`

`= 98\times ( 31 + 24 + 27 ) + 82 \times 2.`

`= 98\times82+82\times2.`

`= 82\times(98+2).`

`= 82 . 100.`

`= 8200.`

`d)` `8\times9\times14 + 6\times17\times12 + 19\times4\times18.`

`= 2\times4\times9\times14+2\times3\times17\times12+19\times2\times2\times18.`

`= 36\times2\times14+36\times2\times17+36\times19\times2.`
`= 36\times28+36\times34+36\times38.`
`= 36\times(28+34+38).`
`= 36\times100.`

`= 3600.`

`e)` `(22+44+66+...+1000)\times(95\times222-190\times111).`

`= (22+44+66+...+1000)\times(95\times111\times2-190\times111).`

`= (22+44+66+...+1000)\times(190\times111-190\times111).`

`= (22+44+66+...+1000)\times[111\times(190-190)].`

`= (22+44+66+...+1000)\times(111\times0).`

`= (22+44+66+...+1000)\times0.`

`= 0.`

a) 5871 : [ 928 - ( 247 - 82) . 5] = 5871 : [ 928 - 825 ]

    5871 : [ 928 - ( 247 - 82) . 5] = 5871 : 103 = 57

b) 33. 75 + 25.33 - 280 = 33 . ( 75 + 25) - 280

    33. 75 + 25.33 - 280 = 33 . 100 - 280                                          

    33. 75 + 25.33 - 280 = 3300 - 280 = 3020

c) 98. 31 + 98.24 + 98. 27 + 2.82

= 98 . ( 31 + 24 + 27 ) + 82 x 2

= 98 . 82 + 82 . 2 = 82 . ( 98 + 2 ) 

= 82 . 100 = 8200

d) 8 . 9 . 14 + 6 . 17 . 12 + 19 . 4 . 18

= 2 . 2 . 2 . 3 . 3 . 2 . 7 + 2 . 3 . 17 . 2 . 2 . 3 + 19 . 2 . 2 . 2 . 3 . 3

= 8 . 9 . 7 + 9 . 8 . 17 + 19 . 8 . 9
= 72 . 7 + 72 . 17 + 72 .19
= 72 . ( 7 + 17 + 19 ) 
= 72 . 43 = 3096

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