30240 : x = 42 x x 12 = 2412 x x 37 = 1135 25 x x = 9100 . ( x + 3 ) x 247 = 40755 57316 : ( x - 8 ) = 623 2016 - x : 3 = 435; 2015 : 5 + x = 817 ;

` 30240 : x = 42 ` 

` x = 30240 : 42 `

` x = 720 `

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` x xx 12 = 2412 `

` x = 2412 : 12 `

` x = 201 `

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` x xx 37 = 1135 `

` x = 1135 : 37 `

` x = 1135/37 `

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` 25 xx x = 9100 `

` x = 9100 : 25 `

` x = 364 `

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` ( x + 3 ) xx 247 = 40755 `

` x + 3 = 40755 : 247 `

` x + 3 = 165 `

` x = 165 - 3 `

` x = 162`

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` 57316 : ( x - 8 ) = 623 `

` x - 8 = 57316 : 623 `

` x - 8 = 92 `

` x = 92 + 8 `

` x = 100 `

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` 2016 - x : 3 = 435 `

` x : 3 = 2016 - 435 `

` x : 3 = 1581 `

` x = 1581 xx 3 `

` x = 4743 `

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` 2015 : 5 + x = 817 `

` 403 + x = 817 `

` x = 817 - 403 `

` x = 414 `

Đáp án + Giải thích các bước giải:

`30240 : x = 42`

`x = 30240 : 42`

`x = 720`

_______________________

`x xx 12 = 2412`

`x = 2412 : 12`

`x = 201`

_______________________

`x xx 37 = 1135`

`x = 1135 : 37`

`x = 1135/37`

______________________

`25 xx x = 9100`

`x = 9100 : 25`

`x = 364`

_______________________

`(x + 3) xx 247 = 40755`

`x + 3 = 40755 : 247`

`x + 3 = 165`

`x = 165 - 3`

`x = 162`

_______________________

`57316 : ( x - 8 ) = 623`

`x - 8 = 57316 : 623`

`x - 8 = 92`

`x = 92 + 8`

`x = 100`

_______________________

`2015 : 5 + x = 817`

`403 + x = 817`

`x = 817 - 403`

`x = 414`