Tính nhanh: a) 72,64 – ( 18,35 + 9,29) b) 45,83 – 8,46 – 7,37 c) 1,47 x 36 + 1,47 x 36 d) 25,8 x 1,02 – 25,8 x 1,01

Đáp án:

c) `1,47` x `3``6` + `1,47` x `3``6`

`=``(`1,47`  x  `36` `)`    x    `2`

`=``105,84`

d) 25,8 x 1,02 – 25,8 x 1,01

`=``25,8` x `(``1,02``-``1,01``)`

`=``25,8` x `0,01`

`=``0,258`

a) `72,64 ``–`` ( ``18,35 ``+`` 9,29``)`

`=``72,64` `-` `18,35` `-` `9,29`

`=``(``72,64``-``9,29``)``-``18,35`

`=``63,35``-``18,35`

`=` `45`

b)`45,83`` –`` 8,46``– ``7,37`

`=``(``45,83``-``7,37``)``-``8,46`

`=``38,46``-``8,46`

`=``30`

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