Question

Tính nhẩm.

Answer 1

` 2xx 4 = 8`

` 2xx7 = 14`

` 2xx1 = 2 `

` 2xx5 = 10 `

`2xx2 = 4 `

`2xx 10 = 20`

`2xx8=16`

`2xx6=12`

`2xx9=18`

`2xx3=6`

Answer 2

Ta có : 

` 2 xx 4 = 8 ; 2 xx 7 = 14 ; 2 xx 1 = 2 ; 2 xx 5 = 10 ; 2 xx 2 = 4 ; 2 xx 10 = 20 ; 2 xx 8 = 16 ; 2 xx 6 = 12 `

` 2 xx 9 = 18 ; 2 xx 3 = 6 ` .