64 x 867 + 867 x 36 - 30 x 867

= 867 x ( 64 + 36 - 30 )

= 867 x 70

= 60 690

\(64\times867+867\times36-30\times867\)

\(=867\times\left(64+24-30\right)\)

\(=867\times70\)

\(=60690\)

2013 x 867 + 132 x 2013 + 2083

= 2013 x 867 + 132 x 867 + 2013 + 70 

= 2013 x ( 867 + 132 + 1 ) + 70

= 2013 x 1000 + 70

= 2013070

2013 x 867 + 132 x 2013 + 2013 + 70

= 2013 ( 867 + 132 + 1 ) + 70

= 2013 x 1000 + 70

= 2013070

hok tốt

86,718 > 86,7xx

>> xx = 11

Vì 86,718 > 86,711

Vì đề bài có đôi phần vô lý nên mik đã sửa ạ.

3,75 x N + N x 4,92 = 867

N x (3,75 + 4,92) = 867

N x 8,67 = 867

N = 100            

N ( 3,75 + 4,92 ) =867

N .8,67              =867

N                       = 867 :8,67

N                       =100

326 x 728+ 327 × 272  =

237328+88944=  326272

2008 ×867+ 2009× 133 =

1740936+267197=2008133

nhớ k minh nha

a, 326 x 728 + 327 x 272

= ( 326 + 1 ) x 728 + 327 x 272

= 327 x 728 + 327 x 272 

= 327 x ( 728 + 272 ) 

= 327 x 1000

= 327000

b, 2008 x 867 + 2009 x 133

= ( 2008 + 1 ) x 867 + 2009 x 133

= 2009 x 867 + 2009 x 133

= 2009 x ( 867 + 133 ) 

= 2009 x 1000

= 2009000

Tính bằng cách thuận tiện nhất :

a. 67 x 126 - 67 x 84 - 41 x 67 - 67

= 67 x 126 - 67 x 84 - 41 x 67 - 67 x 1

= 67 ( 126 - 84 - 41 - 1 )

= 67 x 0

=0

b. 36 x 2 x 2 + 7 x 28

=  2 ( 36 x 2 + 14 x 7 )  

= 2 x 170

= 340

c. 24 x 18 + 12 x 64

= 12 x 2 x 18 + 12 x 64

= 12 ( 2 x 18 + 64)

= 12 x 100

= 1200

a. 67 x 126 - 67 x 84 - 41 x 67 - 67

= 67 x 126 - 67 x 84 - 41 x 67 - 67 x 1

= 67 ( 126 - 84 - 41 - 1 )

= 67 x 0

=0

b. 36 x 2 x 2 + 7 x 28

=  2 ( 36 x 2 + 14 x 7 )  

= 2 x 170

= 340

c. 24 x 18 + 12 x 64

= 12 x 2 x 18 + 12 x 64

= 12 ( 2 x 18 + 64)

= 12 x 100

= 1200

`@` `\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`

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

=326000+272

=326272

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

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

a.         63x45+63x55 

   =63x(45+55) 

   =63x100 

   =6300 

b.         546,43 + 64 x 546,43 + 36 

     KO tính nhanh dc nha

          (chắc đề sai)

63 . 45 + 63 . 55...........................

= 63 ( 45 + 55 )..........................

= 63 . 100 = 6300..............

\(419:\left(8\times8\times4,18+0,17\times2,5+2,09\times2\times36+0,23\times2,5\right)\)

\(=419:\left(64\times4,18+0,17\times2,5+4,18\times36+0,23\times2,5\right)\)

\(=419:\left[\left(64+36\right)\times4,18+\left(0,17+0,23\right)\times2,5\right]\)

\(=419:\left[100\times4,18+0,4\times2,5\right]\)

\(=419:\left[418+1\right]\)

\(=419:419\)

\(=1\)

\(=\dfrac{419}{64\cdot4.18+0,17\cdot2,5+2,09\cdot72+0,23\cdot2,5}\)

\(=\dfrac{419}{0,4\cdot2,5+64\cdot4,18+2,09\cdot72}\)

\(=\dfrac{419}{1+418}=1\)