a) \(1-\frac{13}{17}=\frac{4}{17}\) và \(1-\frac{15}{19}=\frac{4}{19}\)

Vì \(\frac{4}{17}>\frac{4}{19}\)nên \(\frac{13}{17}>\frac{15}{19}\)

b) \(\frac{12}{48}=\frac{1}{4}\) và \(\frac{9}{36}=\frac{1}{4}\)

Vì \(\frac{1}{4}=\frac{1}{4}\)nên \(\frac{12}{48}=\frac{9}{36}\)

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mơn bạn nhiều

câu 1

125875/125871

câu 2

a) 13/17 < 15/19

b) 12/48 = 9/36

a) \(1-\frac{13}{17}=\frac{4}{17}\) và \(1-\frac{15}{19}=\frac{4}{19}\)

Vì 4/17 > 4/19 nên 13/17 < 15/19      

b) \(\frac{12}{48}=\frac{1}{4}\) và \(\frac{9}{36}=\frac{1}{4}\)

Vậy 12/48 = 9/36

13/17<15/19

12/48=9/36

**** tớ nhha

ta có thể lấy 4/17+13/17=1.

ta có thể lấy 4/19+15/19=1

ta so sanh 4/17 > 4/19

nên 13/17 > 15/19

a) Ta có :\(\frac{12}{18}< \frac{12}{17}\)

Mà : \(\frac{12}{17}< \frac{13}{17}\)

Từ đó : \(\frac{12}{18}< \frac{13}{17}\)

Thế còn câu b thì sao  bạn  ?

b) Ta có : \(\frac{31}{90}>\frac{30}{90}=\frac{1}{3}\)

Mà : \(\frac{16}{51}< \frac{17}{51}=\frac{1}{3}\)

Từ đó : \(\frac{16}{51}< \frac{31}{90}\)

a/Ta có: \(\frac{7}{13}+\frac{6}{13}=1\)     ;\(\frac{17}{23}+\frac{6}{23}=1\)

Vì \(\frac{6}{13}>\frac{6}{23}\)nên\(\frac{7}{13}< \frac{17}{23}\)

b/Ta có: \(\frac{12}{48}< \frac{12}{47}\) ;     \(\frac{12}{47}< \frac{13}{47}\)\(\Rightarrow\frac{12}{48}< \frac{13}{47}\)

23/24>12/13

\(\frac{12}{13}\)<\(\frac{23}{24}\)

a)13/17 va 15/19

1>13/17

1>15/19

vay13/17<15/19

b)12/48 va 9/36

12/48=1/4

9/36=1/4

1/4=1/4

vay:12/48=9/36

mk nhanh nhat cho mk **** nhe

\(\frac{13}{17}< \frac{15}{19}\)

\(\frac{12}{48}=\frac{9}{36}\)

giải:

Ta có:

\(A=\frac{-9}{10^{2010}}+\frac{-19}{10^{2011}}=\frac{-9}{10^{2010}}+\frac{-9-10}{10^{2011}}=\frac{-9}{10^{2010}}+\frac{-9}{10^{2011}}+\frac{-10}{10^{2011}}\)

\(B=\frac{-9}{10^{2011}}+\frac{-19}{10^{2010}}=\frac{-9}{10^{2011}}+\frac{-9-10}{10^{2010}}=\frac{-9}{10^{2011}}+\frac{-9}{10^{2010}}+\frac{-10}{10^{2010}}\)

Vì \(\frac{10}{10^{2011}}< \frac{10}{10^{2010}}\rightarrow\frac{-10}{10^{2011}}>\frac{-10}{10^{2010}}\Rightarrow\frac{-9}{10^{2010}}+\frac{-9}{10^{2011}}+\frac{-10}{10^{2011}}>\frac{-9}{10^{2011}}+\frac{-9}{10^{2010}}+\frac{-10}{10^{2010}}\)

Vậy \(A>B\)( Bạn nhớ đọc kĩ lời giải nhé)