A)1212/1313<1313/1414.B)1717/2525<515151/727272.23/28,7/9,5/7,11/18

a) \(\dfrac{12}{14}=\dfrac{1200}{1400}=\dfrac{1400-200}{1400}=1-\dfrac{200}{1400}\)

\(\dfrac{1212}{1414}=\dfrac{1414-200}{1414}=1-\dfrac{200}{1414}\)

vì \(\dfrac{200}{1414}< \dfrac{200}{1400}\)

Nên \(1-\dfrac{200}{1400}< 1-\dfrac{200}{1414}\)

Vậy \(\dfrac{12}{14}< \dfrac{1212}{1414}\)

Các bài sau tương tự

Ai làm đúng và nhanh nhất mk k cho

cái thứ hai lớn hơn

Ta có : \(\frac{1212+1313+1414+1515+1616}{1717+1818+1919+2020+2121}=\frac{12+13+14+15+16}{17+18+19+20+21}=\frac{28\cdot\frac{5}{2}}{38\cdot\frac{5}{2}}=\frac{14}{19}\)

Dễ thấy \(\frac{111111}{666665}< \frac{1}{2}\) ( do 111111 < 666665/2 ) và \(\frac{14}{19}>\frac{1}{2}\) ( do 14 > 19/2 )

Vậy \(\frac{111111}{666665}< \frac{1212+1313+1414+1515+1616}{1717+1818+1919+2020+2121}\)

ta có: \(\frac{1717}{2525}=\frac{17}{25}\)

\(\frac{515151}{727272}=\frac{51}{72}=\frac{17}{24}>\frac{17}{25}\)

\(\Rightarrow\frac{1717}{2525}< \frac{515151}{727272}\)

Ta có:

\(\frac{1717}{2525}=\frac{17}{25}\)

\(\frac{515151}{727272}=\frac{51}{72}=\frac{17}{24}\)

Mà: \(\frac{17}{25}< \frac{17}{24}\)

\(\Rightarrow\frac{1717}{2525}< \frac{515151}{727272}\)

tks 2 bạn nha

a )   − 1212 − 2424 = ( − 1212 ) : ( − 1212 ) ( − 2424 ) : ( − 1212 ) = 1 2

b )   120120 − 240240 = 120120 : ( − 120120 ) − 240240 : ( − 120120 ) = − 1 2

c)  1313 − 1414 = 1313 : ( − 101 ) − 1414 : ( − 101 ) = − 13 14

\(\frac{1717}{2525}=\frac{17}{25};\frac{515151}{727272}=\frac{51}{72}\)

Ta có : \(\frac{17}{25}

\(\frac{1717}{2525}=\frac{17}{25}\)

\(\frac{515151}{727272}=\frac{17}{24}\)

Cùng tử, ta có : 25 > 24

=> \(\frac{17}{25}

a) 33 66 = 33 : 33 66 : 33 = 1 2 b ) − 22 77 = − 22 : 11 77 : 11 = − 2 7

c ) 3030 6060 = 3030 : 3030 6060 : 3030 = − 1 2 d ) − 1212 − 2424 = ( − 1212 ) : ( − 1212 ) ( − 2424 ) : ( − 1212 ) = 1 2

e ) 120120 − 240240 = 120120 : ( − 120120 ) − 240240 : ( − 120120 ) = − 1 2

f ) 1313 − 1414 = 1313 : ( − 101 ) − 1414 : ( − 101 ) = − 13 14