\(62\cdot10:\left\{780:\left[103-\left(2\cdot53+35\cdot14\right)\right]\right\}\)

\(=62\cdot10:\left\{780:\left[103-596\right]\right\}\)

\(=620:\dfrac{-780}{493}\)

\(=620\cdot\dfrac{-493}{780}=\dfrac{-15283}{39}\)

\(a,\left\{\left[\left(37+13\right):5\right]-45:5\right\}.7\)

\(=\left\{\left[50:5\right]-45:5\right\}.7\)

\(=\left\{10-45:5\right\}.7\)

\(=\left\{10-9\right\}.7\)

\(=1.7=7\)

\(6^2.10:\left\{780:\left[10^3-\left(2.5^3+35.14\right)\right]\right\}\)

\(=36.10:\left\{780:\left[1000-\left(2.125+35.14\right)\right]\right\}\)

\(=360:\left\{780:\left[1000-\left(250+490\right)\right]\right\}\)

\(=360:\left\{780:\left[1000-740\right]\right\}\)

\(=360:\left\{780:260\right\}\)

\(=360:3=120\)

a) 12/37 < 19/54

b) 18/53 > 26/78

c)  13/79    <    34/204

d) 25/103   <   74/295

e)  58/63     <    36/55

g)  456/461   >     123/128

giải rõ cho mình dk ko

a) Ta có: 12/37<12/36=1/3 ; 19/54>19/57=1/3 => 12/37<19/54

b) Ta có: 18/53>18/54=1/3 ; 26/78=1/3 => 18/53>26/78

c) Ta có: 13/79<13/78=1/6 ; 34/204=1/6 => 13/79<34/204

d) Ta có: 25/103<25/100=1/4=74/296<74/295 => 25/103<74/295

e) Ta có: 58/63>54/63=6/7=36/42>36/55 => 58/63>36/55

g) Phần bù so với 1 của p/s 456/461 là: 1- 456/461= 5/461

    Phần bù so với 1 của p/s 123/128 là: 1- 123/128= 5/128 

    Vì 5/461< 5/128 nên 456/461>123/128  

a,số các số hạng là 

41-5 :3 + 1 = 13

tổng là 

(5 + 41 )x 13 : 2 = 299

b, tổng = -106

a 

5+8+11+14+...+38+41

=(41-5):3+1]:2 . 46

=13

a) 5+8+11+14+...+38+41

  SSH : 

   ( 41 - 5 ) : 3+ 1 = 13

Tổng trên: 

   ( 41 + 5 ) x 13 : 2 = 299

  Đáp số:... 

\(\dfrac{25}{27};\dfrac{51}{53};\dfrac{47}{49};\dfrac{103}{105};\dfrac{2009}{2011};\dfrac{1963}{1963};\)

25/27,47/49,51/53,103/105,2009/2011,1963/1963.

25/27,51/53,47/49,103/105,2009/2011,1963/1963

a ) 3/5;33/55;333/555

33:11/55:11=3/5 ; 333:111/555:111=3/5

b)101/103;101101/103103

101101:1001/103103:1001=101/103

a, 71.2 – 6.(2x+5) =  10 5 : 10 3

71.2 – 6.(2x+5) =  10 2

6.(2x+5) = 71.2 – 100

6.(2x+5) = 42

x = 1

b,  5 x + 3 4 . 6 8 = 6 9 . 3 4

5 x + 3 4 . 6 8 = 6 8 . 6 . 3 4

5 x + 3 4 = 6 8 . 6 . 3 4 : 6 8 = 6 . 3 4

5x =  6 . 3 4 - 3 4 = 5 . 3 4

x =  3 4

c, 12:{390:[5. 10 2  – ( 5 3 + x . 7 2 )]} = 4

390:[5. 10 2  – ( 5 3 + x . 7 2 )] = 12:4 = 3

5. 10 2  – ( 5 3 + x . 7 2 ) = 390:3 = 130

5 3 + x . 7 2 = 5. 10 2  – 130 = 370

x . 7 2 = 370 –  5 3 = 245

x = 245: 7 2 = 5

d,  5 3 .(3x+2):13 =  10 3 : 13 5 : 13 4

5 3 .(3x+2):13 =  10 3 : 13

3x+2 =  10 3 : 13 : 5 3 .13 = 8

x = 2

help

a: \(\dfrac{25}{26}=1-\dfrac{1}{26}\)

\(\dfrac{50}{51}=1-\dfrac{1}{51}\)

mà \(-\dfrac{1}{26}< -\dfrac{1}{51}\)

nên \(\dfrac{25}{26}< \dfrac{50}{51}\)

b: \(\dfrac{149}{157}=1-\dfrac{8}{157}\)

\(\dfrac{449}{457}=1-\dfrac{8}{457}\)

mà \(-\dfrac{8}{157}>-\dfrac{8}{457}\)

nên \(\dfrac{149}{157}>\dfrac{449}{457}\)

Chọn C