So sánh:
câu a:A=\(\frac{33.10^3}{2^3.5.10^3+7000}\)B=\(\frac{3774}{5217}\)
câu b:A=\(\frac{4}{7}\)+5+ \(\frac{3}{7^2}\)+\(\frac{5}{7^2}\)+\(\frac{5}{7^3}\)+\(\frac{6}{7^4}\)
B=\(\frac{5}{7^4}\)+ 5 + \(\frac{6}{7^2}\)+ \(\frac{4}{7}\)+\(\frac{5}{7^3}\)
câu a
\(A=\frac{33.10^3}{2^3.5.10^3+7000}=\frac{33.10^3}{2^3.5.10^3+7.10^3}=\frac{33.10^3}{10^3\left(2^3.5+7\right)}=\frac{33.10^3}{10^3.47}=\frac{33}{47}\)
\(B=\frac{3774}{5217}=\frac{34.111}{47.111}=\frac{34}{47}\)
\(\Rightarrow\frac{33}{47}< \frac{34}{47}\)
=> A<B