Question

tính nhanh: 

1001\(^2\) 

29,9.30,1

201\(^2\)

37.43

Answer 1

\(1001 ^2=( 1000 + 1 ) ^2=1000000 + 2000 + 1=1002001 \)

\(29,9.30,1=( 30 − 0 , 1 ) ( 30 + 0 , 1 )=900 − 0 , 01 = 899 , 99\)

\(201 ^2=( 200 + 1 ) ^2=40000 + 400 + 1 = 40401 \)

\(37.43= ( 40 − 3 ) ( 40 + 3 ) =1600 − 9 = 1591\)

Answer 2

`1001^2`

`=(1000+1)^2`

`=1000^2 + 2.1000.1 + 1^2`

`=1000000 + 2000 + 1`

`=1002001`

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`29,9 . 30,1`

`=(30-0,1).(30+0,1)`

`=30^2 - (0,1)^2`

`=900 - 0,01`

`=899,99`

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`201^2`

`=(200+1)^2`

`=200^2 + 2.200.1 +1^2`

`=40000 + 400 + 1`

`=40401`

__________________________________

`37.43`

`=(40-3).(40+3)`

`=40^2 - 3^2`

`=1600 - 9`

`=1591`

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`#LeMichael`