c ) 815 - 23 - 77 + 185 

= ( 815 + 185 ) - ( 23 + 77 )

= 1000 - 100 = 900

m ) 8 x 427 x 3 + 6 x 573 x 4

= 24 x 427 + 24 x 573

= 24 x ( 427 + 573 ) 

= 24 x 1000

= 24000

g ) 52 - 42 + 37 + 28 - 38 + 63

= ( 52 + 28 ) - ( 42 + 38 ) + ( 37 + 63 )

= 80 - 80 + 100

= 0 + 100

= 100

h ) 35 x 18 - 9 x 70 + 100

= 7 x 5 x 9 x 2 - 9 x 7 x 5 x 2 + 100

= 0 + 100

= 100

n ) 2008 x 867 + 2009 x 133

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

= 2008 x 867 + 2008 x 133 + 133

= 2008 x ( 867 + 133 ) + 133

= 2008 x 1000 + 133

= 2008000 + 133

= 2008133

i ) 326 x 78 + 327 x 22

= 326 x 78 + ( 326 + 1 ) x 22

= 326 x 78 + 326 x 22 + 22

= 326 x ( 78 + 22 )  + 22

= 326 x 100 + 22

= 32600 +22

= 32622

q ) ( 20 + 21 + 22 + 23 + 24 + 25 ) x ( 16 - 2 x 8 ) 

= ( 20 + 21 + 22 + 23 + 24 + 25 ) x ( 16 - 16) 

= ( 20 + 21 + 22 + 23 + 24 + 25 ) x 0

= 0

thank bạn

a: =24*1000=24000

b: =120*1000=120000

c: =72(135+65):25-140

=72*8-140=436

d: =18(957-354-621):72=-9/2

\(A=\dfrac{9}{8}-\dfrac{8}{9}+\dfrac{3}{24}+\dfrac{1}{4}-\dfrac{5}{16}+\dfrac{19}{25}-\dfrac{1}{9}+\dfrac{2}{25}-\dfrac{1}{81}\)

\(=\dfrac{9}{8}+\dfrac{1}{4}-\dfrac{5}{16}+\dfrac{1}{8}-\dfrac{8}{9}-\dfrac{1}{9}-\dfrac{1}{81}+\dfrac{19}{25}+\dfrac{2}{25}\)

\(=\dfrac{10}{8}+\dfrac{1}{4}-\dfrac{5}{16}-1-\dfrac{1}{81}+\dfrac{21}{25}\)

\(=\dfrac{20+4-5}{16}-\dfrac{82}{81}+\dfrac{21}{25}\)

\(=\dfrac{19}{16}-\dfrac{82}{81}+\dfrac{21}{25}\)

\(=\dfrac{32891}{16\cdot81\cdot25}\)

b: \(B=-\dfrac{1}{3}-\dfrac{8}{35}-\dfrac{2}{9}-\dfrac{1}{35}+\dfrac{4}{5}-\dfrac{4}{9}+\dfrac{3}{7}\)

\(=\dfrac{-1}{3}-\dfrac{2}{9}-\dfrac{4}{9}-\dfrac{8}{35}-\dfrac{1}{35}+\dfrac{4}{5}+\dfrac{3}{7}\)

\(=\dfrac{-3-2-4}{9}+\dfrac{-9}{35}+\dfrac{28+15}{35}\)

\(=-1+\dfrac{-9+43}{35}=-1+\dfrac{34}{35}=-\dfrac{1}{35}\)

`Answer:`

1. \(25.\left\{32:[12-4+4.\left(16:8\right)]\right\}\)

 \(=25.\left\{32:[12-4+4.2]\right\}\)

\(=25.\left\{32:[12-4+8]\right\}\)

\(=25.\left\{32:[8+8]\right\}\)

\(=25.\left\{32:16\right\}\)

\(=25.2\)

\(=50\)

2. \(2195.1952-952.427-1952.1768\)

\(=2195.1952-1952.1768-952.427\)

\(=\left(2195-1768\right).1925-952.427\)

\(=427.1952-952.427\)

\(=\left(1952-952\right).427\)

\(=1000.427\)

\(=427000\)

a, 4¹⁰. 2³⁰=2²⁰.2³⁰=2⁵⁰

b,9²⁵.27⁴.81³= 3⁵⁰.3¹².3¹²=3⁷⁴

Tương tự các câu khác....

a, 4¹⁰.2³⁰ = (2²)¹⁰.2³⁰ = 2²⁰.2³⁰ = 2⁵⁰
b, 9²⁵.27⁴.81³ = (3²)²⁵.(3³)⁴.(3⁴)³ = 3⁵⁰.3¹².3¹² = 3⁷⁴
c, 25⁵⁰.125⁵ = (5²)⁵⁰.(5³)⁵ = 5¹⁰⁰.5¹⁵ = 5¹¹⁵
d, 64³.4⁸.16⁴ = (2⁶)³.(2²)⁸.(2⁴)⁴ = 2¹⁸.2¹⁶.2¹⁶ = 2⁵⁰
e, 3⁸ : 3⁶ = 3²
2¹⁰ : 8³ = 2¹⁰ : (2³)³ = 2¹⁰ : 2⁹ = 2
12⁷ : 6⁷ = (12 : 6)⁷ = 2⁷
@Dương Tuyết Mai

\(a,\dfrac{1}{2}=\dfrac{2}{4}=\dfrac{4}{8}=\dfrac{3}{6}\\ b,\dfrac{1}{4}=\dfrac{2}{8}=\dfrac{3}{12}=\dfrac{5}{20}\\ c,\dfrac{2}{5}=\dfrac{8}{20}=\dfrac{10}{25}\)

Tui cux k bt nữa tui tính rồi mà tinhs mãi k ra 

Bà bt ln chưa chỉ tôi vs

\(\dfrac{37\cdot5^4}{25^2}=\dfrac{37\cdot5^4}{5^4}=37\\ \dfrac{2^4\cdot2^6\cdot3^8\cdot9^2}{4^4\cdot3^{11}}=\dfrac{2^{10}\cdot3^8\cdot3^4}{2^8\cdot3^{11}}=2^2\cdot3=12\\ \dfrac{3\cdot9^4\cdot9^3}{3^2\cdot9}=\dfrac{3\cdot3^8\cdot3^6}{3^2\cdot3^2}=3^{11}\\ \dfrac{125\cdot5\cdot64-25^3\cdot10\cdot4}{5^7\cdot8}=\dfrac{5^3\cdot5\cdot2^6-5^6\cdot2\cdot5\cdot2^2}{5^7\cdot2^3}=\dfrac{5^4\cdot2^3\left(2^3-5^3\right)}{5^7\cdot2^3}=\dfrac{8-125}{5^3}=\dfrac{-117}{125}\)