Question

So sánh hai phân số \(A=\frac{10^{15}+1}{10^{16^{ }}+1}\) và \(B=\frac{10^{16+1}}{10^{17^{ }}+1}\)

Answer 1

\(\frac{10^{15}+1}{10^{16}+1}=\frac{10^{16}+10}{10^{17}+10}\)

Vì B<1 suy ra B<\(\frac{10^{16}+1+9}{10^{17}+1+9}=\frac{10^{16}+10}{10^{17}+10}=A\)

Vậy B<A

Answer 2

Ta có: \(10A=\frac{10^{16}+10}{10^{16}+1}=1+\frac{9}{10^{16}+1}\) ; \(10B=\frac{10^{17}+10}{10^{17}+1}=1+\frac{9}{10^{17}+1}\)

Mà \(\frac{9}{10^{16}+1}>\frac{9}{10^{17}+1}\) nên \(10A>10B\) => \(A>B\)