Giúp em nha em đang cần

Đáp án + Giải thích các bước giải:

 1. a) `67 + 135 + 33`

`= ( 67 + 33 ) + 135`

`= 100 + 135 = 235`

b) `277 + 113 + 323 + 87`

`= ( 277 + 323 ) + ( 113 + 87 )`

`= 600 + 200 = 800`

2. a) `8 . 17 . 125`

`= ( 8 . 125 ) . 17`

`= 1000 . 17 = 17000`

b) `4 . 37 . 25`

`= ( 4 . 25 ) . 37`

`= 100 . 37 = 3700`

c) `5 . 125 . 2 . 41 . 8`

`= ( 5 . 2 ) . ( 125 . 8 ) . 41`

`= 10 . 1000 . 41 = 10000 . 41 = 410000`

d) `25 . 7 . 10 . 4`

`= ( 25 . 4 ) . ( 7 . 10 )`

`= 100 . 70 = 7000`

e) `8 . 12 . 125 . 2`

`= ( 8 . 125 ) . ( 12 . 2 )`

`= 1000 . 24 = 24000`

f) `4 . 36 . 25 . 50`

`= ( 4 . 25 ) . ( 36 . 50 )`

`= 100 . 1800 = 180000`

3. a) `37 . 38 + 62 . 37`

`= 37 . ( 38 + 62 )`

`= 37 . 100 = 3700`

b) `43 . 11`

`= 43 . ( 10 + 1 )`

`= 43 . 10 + 43 . 1 = 430 + 43 = 473`

`67 . 101`

`= 67 . ( 100 + 1 )`

`= 67 . 100 + 67 . 1 = 6700 + 67 = 6767`

`423 . 1001`

`= 423 . ( 1000 + 1 )`

`= 423 . 1000 + 423 . 1 = 423000 + 423 = 423423`

c) `67 . 99`

`= 67 . ( 100 - 1 )`

`= 67 . 100 - 67 . 1 = 6700 - 67 = 6633`

d) `43 . 11`

`= 43 . ( 10 + 1 )`

`= 43 . 10 + 43 . 1 = 430 + 43 = 473`

f) `67 . 101`

`= 67 . ( 100 + 1 )`

`= 67 . 100 + 67 . 1 = 6700 + 67 = 6767`

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