Question

1, Tính nhanh 

a) 18x28+36x36

b) 24000-36x75-36x25

c) 2045-382+955-618

Answer 1

`a,18xx28+36xx36`

`=18xx28+18xx2xx36`

`=18xx28+18xx72`

`=18xx(28+72)`

`=18xx100`

`=1800`

`b,24000-36xx75-36xx25`

`=24000-(36xx75+36xx25)`

`=24000-36xx(75+25)`

`=24000-36xx100`

`=24000-3600`

`=20400`

`c,2045-382+955-618`

`=(2045+955)-(382+618)`

`=3000-1000`

`=2000`

Answer 2

1, Tính nhanh 

a) 18 x 28 + 36 x 36

= (18 x 28) + (36 x 36)

= 504 + 1296

= 1800

b) 24000 - 36 x 75 - 36 x 25

= 24000 - [36 x 75 - 36 x 25]

= 24000 - [36 x (75 + 25)]

= 24000 - [36 x 100]

= 24000 - 3600

= 20400

c) 2045 - 382 + 955 - 618

= (2045 - 382) + (955 - 618)

= 1663 + 337

= 1000.

Answer 3

a. 18 x 28 + 36 x 36

 (18 x 28) + (36 x 36)

 504 + 1296

 1800

b. 24000 - 36 x 75 - 36 x 25

 24000 - (36 x 75 - 36 x 25)

 24000 - (36 x (75 + 25)

 24000 - (36 x 100]

 24000 - 3600

 20400

c. 2045 - 382 + 955 - 618

 (2045 - 382) + (955 - 618)

 1663 + 337

 1000.

Answer 4

a) 1800

b)20400

c)2000

 

Answer 5

1, Tính nhanh 

a) 18 x 28 + 36 x 36

= (18 x 28) + (36 x 36)

= 504 + 1296

= 1800

b) 24000 - 36 x 75 - 36 x 25

= 24000 - [36 x 75 - 36 x 25]

= 24000 - [36 x (75 + 25)]

= 24000 - [36 x 100]

= 24000 - 3600

= 20400

c) 2045 - 382 + 955 - 618

= (2045 - 382) + (955 - 618)

= 1663 + 337

= 1000