Question

bài 12 tính nhanh 
a, 326 x 728 + 327 x 272      b 2008 x 867 + 2009 x 133 
c, 1235 x 6789 x(630 - 315 x2 )   d (m : 1 - m x 1 ) : ( m x 2008 + m + 2008)
ai xog trc em tich nhé

 

Answer 1

`@` `\text {Ans}`

`\downarrow`

`a,`

\(\text{326 x 728 + 327 x 272}\)

`= 326 \times 728 + 326 \times 272 + 272`

`= 326 \times (728 + 272) + 272`

`= 326 \times 1000 + 272`

`= 362000 + 272`

`= 362272`

`b,`

\(\text{2008 x 867 + 2009 x 133}\)

`= 2008 \times 867 + 2008 \times 133 + 133`

`= 2008 \times (867 + 133) + 133`

`= 2008 \times 1000 + 133`

`= 2008000 + 133`

`= 2008133`

`c,`

\(\text{1235 x 6789 x (630 - 315 x 2 )}\)

`= 1235 \times 6789 \times (630 - 630)`

`= 1235 \times 6789 \times 0`

`= 0`

`d,`

\((m \div 1 - m \times 1 ) \div ( m \times 2008 + m + 2008)\)

`= (m - m) \div (m \times 2008 + m + 2008)`

`= 0 \div (m \times 2008 + m + 2008)`

`= 0`

Answer 2

a: =326*728+326*272+272

=326000+272

=326272

c: \(=1235\cdot6789\cdot\left(630-630\right)=0\)

d: \(=\left(m-m\right):\left(20009m+2008\right)=0\)