Ta quy đồng

\(\frac{15}{301}=\frac{15.499}{301.499}=\frac{7485}{150199}\)

\(\frac{25}{499}=\frac{25.301}{499.301}=\frac{7525}{150199}\)

So sánh:

\(\frac{7485}{150199}< \frac{7525}{150199}\)

\(=>\frac{15}{301}< \frac{25}{499}\)

Vậy \(\frac{15}{301}< \frac{25}{499}\)

TA CÓ:

15/301 < 15/300 = 1/20 = 25/500 < 25/499

VÌ: 15/301 < 1/20 < 25/499 NÊN 15/301 < 25/499

25/499 > 15/301

ta có \(\frac{15}{301}=\frac{15.499}{301.499}=\frac{7485}{150199}\)

\(\frac{25}{499}=\frac{25.301}{499.301}=\frac{7525}{150199}\)

mà \(\frac{7485}{150199}< \frac{7525}{150199}\)

⇒ \(\frac{15}{301}< \frac{25}{499}\)

\(\frac{15}{301}< \frac{15}{300}=\frac{1}{20}\)

\(\frac{25}{499}>\frac{25}{500}=\frac{1}{20}\)

\(\Rightarrow\frac{25}{499}>\frac{15}{301}\)

a) Ta có:
\(\frac{15}{301}>\frac{15}{300}=\frac{1}{20}\)

\(\frac{25}{499}< \frac{25}{500}=\frac{1}{20}\)

Vì \(\frac{1}{20}=\frac{1}{20}\) nên \(\frac{15}{301}>\frac{1}{20}>\frac{25}{499}\) hay \(\frac{15}{301}=\frac{25}{499}\)

Vậy \(\frac{15}{301}>\frac{25}{499}\)

a)Ta có:\(\frac{15}{301}\)<\(\frac{15}{300}\)=\(\frac{1}{20}\)=\(\frac{25}{500}\)<\(\frac{25}{499}\)

Vì \(\frac{15}{301}\)<\(\frac{25}{500}\)<\(\frac{25}{499}\)

\(\Rightarrow\)\(\frac{15}{301}< \frac{25}{499}\)(đpcm)

A =  15/301 <  B = 25/499

hihi tui mới học lớp 5 thui 

xin lỗi,mk  ko bt

\(a,A=\dfrac{1}{7.9}\) và \(B=\dfrac{1}{7}-\dfrac{1}{9}\)
\(\Leftrightarrow2A=\dfrac{2}{7.9}=\dfrac{1}{7}-\dfrac{1}{9}\)
Vì \(2A=B\left(=\dfrac{1}{7}-\dfrac{1}{9}\right)\)
\(\Leftrightarrow A< B\)
\(b,A=\dfrac{15}{301}\) và \(B=\dfrac{25}{499}\)
Ta thấy: \(\dfrac{15}{301}< \dfrac{15}{300}\) và \(\dfrac{25}{499}>\dfrac{25}{500}\)
\(\dfrac{15}{300}=\dfrac{1}{20}\) và \(\dfrac{25}{500}=\dfrac{1}{20}\)
Vì \(\dfrac{1}{20}=\dfrac{1}{20}\Leftrightarrow\dfrac{15}{300}=\dfrac{25}{500}\)
\(\Leftrightarrow\dfrac{15}{301}< \dfrac{1}{20}< \dfrac{25}{499}\)
\(\Leftrightarrow\dfrac{15}{301}< \dfrac{25}{499}\)
\(\Leftrightarrow A< B\)
\(c,A=\dfrac{5.6}{9.25}\) và \(B=\dfrac{18.4-18}{8.9+7.9}\)
\(A=\dfrac{5.6}{9.25}=\dfrac{1.2}{3.5}=\dfrac{2}{15}\)
\(B=\dfrac{18.4-18}{8.9+7.9}=\dfrac{18\left(4-1\right)}{9\left(8+7\right)}=\dfrac{18.3}{9.15}=\dfrac{2.1}{1.5}=\dfrac{2}{5}\)
Vì \(\dfrac{2}{15}< \dfrac{2}{5}\)
\(\Leftrightarrow A< B\)
Chúc bạn học tốt!

Là \(A< B\) mà. Cách trên khó hiểu chút. Theo cách này đi.
\(B=\dfrac{1}{7}-\dfrac{1}{9}\)
\(\Leftrightarrow B=\dfrac{2}{7.9}\)
Vì \(\dfrac{1}{7.9}< \dfrac{2}{7.9}\)
\(\Leftrightarrow A< B\)