a.(64 - 32 ) :8 = 32 : 8 = 4 

b. 36 x 2 x7 + 36 x 86

= 36 x (14 + 86)

= 36 x 100

= 3600

   68:8 - 32 : 8

= ( 68 - 32): 8

=    36 : 8

=    4,5

72 x 7 + 36 x 86

= 72 x 7 + 36 x 2 x 43

= 72 x 7 + 72 x 43

= 72 x ( 7 + 43)

= 72 x 50

= 3600

a) 64 : 8 - 32 : 8

=( 64 - 32 ) : 8 

=      32      :  8

=         4

b. 36 x 2 x7 + 36 x 86

= 36 x (14 + 86)

= 36 x 100

= 3600

`= 72 xx 19 + 36 xx 2 xx3 xx 10 + 72 xx 80 - 72 xx 29`

`= 72 xx(19 + 30 - 29 + 80)`

`= 72 xx 100`

`= 7200`

\(=72.19+36.2.3.10+72.2.40-72.29\)

\(=72.19+72.30+72.80-72.29\)

\(=72.\left(19+30+80-29\right)\)

\(=72.100=7200\)

\(86+357+14=457\)

\(72+69+128=275\)

\(25\cdot5\cdot4\cdot27\cdot2=27000\)

\(28\cdot64+28\cdot36=28\left(64+36\right)=2800\)

a) \(86+357+14=\left(86+14\right)+357=100+357=457\)

b) \(72+69+128=\left(72+128\right)+69=200+69=269\)

c) \(25.5.4.27.2=\left(25.4\right).\left(5.2\right).27=100.10.27=27000\)

d) \(28.64+28.36=28\left(64+36\right)=28.100=2800\)

a) \(56^2+44^2+2.56.44=56^2+2.56.44+44^2=\left(56+44\right)^2=100^2=10000\)

b) \(36^2+64^2+72.64=36^2+2.36.64+64^2=\left(36+64\right)^2=100^2=10000\)

c) \(136^2+36^2-72.136=136^2-2.36.136+36^2=\left(136-36\right)^2=100^2=10000\)

a) $56^2+44^2+2.56.44=56^2+2.56.44+44^2=\left(56+44\right)^2=100^2=10000$562+442+2.56.44=562+2.56.44+442=(56+44)2=1002=10000

b) $36^2+64^2+72.64=36^2+2.36.64+64^2=\left(36+64\right)^2=100^2=10000$362+642+72.64=362+2.36.64+642=(36+64)2=1002=10000

c) $136^2+36^2-72.136=136^2-2.36.136+36^2=\left(136-36\right)^2=100^2=10000$

a: \(=68\cdot72\cdot49\cdot\left[324-324\right]=0\)

b: \(=\left(1250-1250\right)\cdot\left(1+...+100\right)=0\)

\(a,\left(68\times72\times49\right)\times\left(27\times12-9\times36\right)=\left(68\times72\times49\right)\times0=0\\ b,\left(25\times50-125\times10\right)\times\left(1+2+...+100\right)=0\times\left(1+2+...+100\right)=0\)

a, ( 68 × 72 × 49 ) × ( 27 × 12 − 9 × 36 ) = ( 68 × 72 × 49 ) × 0 =

b, ( 25 × 50 − 125 × 10 ) × ( 1 + 2 + ... + 100 ) = 0 × ( 1 + 2 + ... + 100 ) = 0

rễ ,chỉ cần gạch thôi

dễ lấy máy tính ra bấm là 618

Ta có 

72+36.2+18.2.6

=36.2+36.2+36.6

=36.(2+2+6)

=36.10

=360 

Dấu . là nhân nha

nham đe rui phương 

chia làm 2 phần: 
36x28+36x82 
+ 
64x69+69x41 

= 
36 x (28+82) 
+ 
69 x (64+41) 

= 
36 x 110 
+ 
69 x 105 

= 
(36 x 100) + (36 x 10) 
+ 
(69 x 100) + (69 x 5) 

= 
3600 + 360 
+ 
6900 + 345 

= 
3960 
+ 
7245 

đáp số: 
11205

\(36.28+36.82+64.69+64.41\)

\(=36\left(28+82\right)+64\left(69+41\right)\)

\(=36.110+64.110\)

\(=110\left(36+64\right)\)

\(=110.100=11000\)