Question

[♡๖²⁴ʱƔĄŠℌ๖ۣۜI๖ۣۜR❍ ŇξŇξ 乂 ℌĄŇĄƘ❍༉♡]

SO SÁNH \(A=\frac{7^{2013}+1}{7^{2014}+1}\)VÀ \(B=\frac{7^{2014}+1}{7^{2015}+1}\)

Answer 1

[Nguyễn Ngọc Anh Minh]

\(\frac{A}{B}=\frac{7^{2013}+1}{7^{2014}+1}.\frac{7^{2015}+1}{7^{2014}+1}=\frac{7^{4028}+7^{2013}+7^{2015}+1}{7^{4028}+2.7^{2014}+1}=\)

\(=\frac{7^{4028}+7^{2013}\left(1+7^2\right)+1}{7^{4028}+2.7.7^{2013}+1}=\frac{7^{4028}+50.7^{2013}+1}{7^{4028}+14.7^{2013}+1}>1\)

\(\Rightarrow A>B\)

Answer 2

[♡๖²⁴ʱƔĄŠℌ๖ۣۜI๖ۣۜR❍ ŇξŇξ 乂 ℌĄŇĄƘ❍༉♡]

A/B sao lại nhân v bn