Question

so sánh 2 phân số

\(\frac{12}{13}\)và\(\frac{1212}{1313}\)                                                         \(\frac{123}{124}\)và \(\frac{124124}{125125}\)

Answer 1

a)Ta có:

\(\frac{1212}{1313}=\frac{12\cdot101}{13\cdot101}=\frac{12}{13}\)

Suy ra \(\frac{12}{13}=\frac{1212}{1313}\)

câu b lạ

Answer 2

a)
Ta có

\(\frac{12}{13}=\frac{12.101}{13.101}=\frac{1212}{1313}\)

\(\Rightarrow\frac{12}{13}=\frac{1212}{1313}\)

b)

Ta có

\(1-\frac{123}{124}=\frac{1}{124}\)

\(1-\frac{124}{125}=\frac{1}{125}\)

Mà  \(\frac{1}{124}>\frac{1}{125}\)

\(\Rightarrow1-\frac{123}{124}>1-\frac{124}{125}\)

\(\Rightarrow\frac{123}{124}< \frac{124}{125}\)

\(\Rightarrow\frac{123}{124}< \frac{124.1001}{125.1001}\)

\(\Rightarrow\frac{123}{124}< \frac{124124}{125125}\)

Answer 3

\(\frac{12}{13}và\frac{1212}{1212}\)

\(\frac{1212}{1313}=\frac{12.101}{13.101}\) \(\Rightarrow\) \(\frac{12}{13}\)

Mà \(\frac{12}{13}=\frac{12}{13}\) \(\Rightarrow\) \(\frac{12}{13}=\frac{1212}{1313}\)

\(\frac{123}{124}\) và \(\frac{124124}{125125}\)

\(1-\frac{123}{124}\) = \(\frac{1}{124}\)

\(1-\frac{124124}{125125}\) = \(\frac{1}{125}\)

Mà \(\frac{1}{124}>\frac{1}{125}\) 

\(\Rightarrow\) \(1-\frac{123}{124}\) > \(1-\frac{124}{125}\)

\(\Rightarrow\) \(\frac{123}{124}\) <\(\frac{124}{125}\) \(\Rightarrow\)  \(\frac{123}{124}\) < \(\frac{124.1001}{125.1001}\)

\(\Rightarrow\) \(\frac{123}{124}< \frac{124124}{125125}\)

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