Question

tính nhanh : 67 . 21 + 33 . 22 

 

Answer 1

`@` `\text {Ans}`

`\downarrow`

`67.21 + 33.22`

`= 67.7.3 + 3.11.22`

`= 3.(67.7 + 22.11)`

`= 3.(469 + 242)`

`= 3. 711`

`= 2133`

Answer 2

67.21+33.22

=(66+1).21+33.(21+1)

=66.21+21+33.21+33

=2.33.21+33.21+21+33

=3.33.21+54

=3.3.11.21+54

=9.(10+1).21+54

=(90+9).21+54

=(100-1).21+54

=2100-21+54

=2133

Answer 3

 Tính nhanh: 

   67 \(\times\) 21 + 33 \(\times\) 22

= 67 \(\times\) 21 + 33 \(\times\) (21 +1)

= 67 \(\times\) 21 + 33 \(\times\) 21 + 33

= 21 \(\times\) (67 + 33) + 33

= 21 \(\times\) 100 + 33

= 2133

Answer 4

Sửa đề: \(67\cdot21+33\cdot21\)

\(=21\cdot\left(67+33\right)\)

\(=21\cdot100\)

\(=2100\)

Answer 5

= 2100