9 7 = 9 × 8 7 × 8 = 72 56 9 8 = 9 × 7 8 × 7 = 63 56 V ì   72 56 > 63 56   n ê n   9 7 > 9 8  

a) \(\frac{114}{121}\) < \(\frac{225}{242}\)

b) \(\frac{114}{115}\) < \(\frac{119}{120}\)

c) \(\frac{2001}{2003}\) > \(\frac{1996}{2006}\)

d) \(\frac{97}{99}\)< \(\frac{98}{100}\)

\(a)MSC:242\)

\(\frac{114}{121}=\frac{228}{242};\frac{225}{242}=\frac{225}{242}\)

\(\Rightarrow\frac{114}{121}>\frac{225}{242}\)

b ) Ta có :

114/115 = 1 - 1/115

119/120 = 1 - 1/120

Mà 1/115 > 1/120 DO đó 1 - 1/115 < 1 - 1/120 HAy 114/115 < 119/120

c ) Ta có :

1996/2006 < 2001/2006 < 2001/2003

=> 1996/2006<2001/2003

d ) Ta có :

97/99 = 1 - 2/99

98/100 = 1 - 2/100

Mà 2/99 > 2/100 Do đó 1 - 2/99 < 1 - 2/100 hay 97/99 < 98/100

Vậy 97/99 < 98/100

a) (100 - 99) + (98 - 97) + ... + (2 - 1) = 1 + 1 + ... + 1 = 50

b) (200 - 199) + (198 - 197) + ... + (2 - 1) = 1 + 1 + ... + 1 = 100

\(\dfrac{97}{100}\)  và \(\dfrac{98}{99}\)

\(\dfrac{97}{100}=\dfrac{97\times99}{100\times99}=\dfrac{9603}{9900}\)

\(\dfrac{98}{99}=\dfrac{98\times100}{99\times100}=\dfrac{9800}{9900}\)

Vì: \(9603< 9800\)  nên => \(\dfrac{97}{100}< \dfrac{98}{99}\)

\(\dfrac{13}{17}\)  và \(\dfrac{131}{171}\)

\(\dfrac{13}{17}=\dfrac{13\times171}{17\times171}=\dfrac{2223}{2907}\)

\(\dfrac{131}{171}=\dfrac{131\times17}{171\times17}=\dfrac{2227}{2907}\)

Vì: \(2227>2223\)  nên: => \(\dfrac{13}{17}< \dfrac{131}{171}\)

\(\dfrac{51}{61}\)  và \(\dfrac{515}{616}\)

\(\dfrac{51}{61}=\dfrac{51\times616}{61\times616}=\dfrac{31416}{37576}\)

\(\dfrac{515}{616}=\dfrac{515\times61}{616\times61}=\dfrac{31415}{37576}\)

Vì: \(31416>31415\)  Nên => \(\dfrac{51}{61}>\dfrac{515}{616}\)

a/

$\frac{97}{100}< \frac{98}{100}< \frac{98}{99}$

c/

$\frac{131}{171}=1-\frac{40}{171}> 1-\frac{40}{170}=1-\frac{4}{17}=\frac{13}{17}$
d/

$\frac{51}{61}=1-\frac{10}{61}=1-\frac{100}{610}$

$\frac{515}{616}=1-\frac{101}{616}$

Xét hiệu:

$\frac{100}{610}-\frac{101}{616}=\frac{100.616-101.610}{610.616}$

$=\frac{100(610+6)-101.610}{610.616}$

$=\frac{600-610}{610.616}<0$

$\Rightarrow \frac{100}{610}< \frac{101}{616}$

$\Rightarrow 1-\frac{100}{610}> 1-\frac{101}{616}$

$\Rightarrow \frac{51}{61}> \frac{515}{616}$ 

\(a,\frac{8}{9}< \frac{108}{109}\)

\(b,\frac{97}{100}< \frac{98}{99}\)

\(c,\frac{19}{18}>\frac{2017}{2016}\)

\(d,\frac{15}{16}>\frac{515}{616}\)

dễ mà bạn lấy 1 trừ cho phân số

1-96 97=1 97

1-95 96=1 96

1 96>1 97 nha

vậy 95 96>96 97

mik lớp 5 nha

Lời giải:

\(A=\frac{98^{12}+1}{98^{13}+1}\\ 98A=\frac{98^{13}+98}{98^{13}+1}=1+\frac{97}{98^{13}+1}> 1+\frac{97}{98^{14}+1}=\frac{98^{14}+98}{98^{14}+1}=98.\frac{98^{13}+1}{98^{14}+1}=98B\)

$\Rightarrow A>B$

Ta có: 95/96 = 1 - 1/96

96/97 = 1 - 1/97

Do 1/96 > 1/97

=> 1 - 1/96 < 1 - 1/97

=> 95/96 < 96/97