Question

A = 2^2020 - 1/ 2^2021 - 1 và B = 2^2021 - 1/ 2^2022 - 1

Answer 1

\(2A=\dfrac{2^{2021}-1-1}{2^{2021}-1}=1-\dfrac{1}{2^{2021}-1}\)

\(2B=\dfrac{2^{2022}-1-1}{2^{2022}-1}=1-\dfrac{1}{2^{2022}-1}\)

mà \(2^{2021}-1< 2^{2022}-1\)

nên A<B

Answer 2

$A=\frac{{}^{}-1}{{}^{}-1}$

$\Rightarrow 2A=\frac{2.({}^{}-1)}{{}^{}-1}$

$\Rightarrow 2A=\frac{{}^{}-2}{{}^{}-1}$

$\Rightarrow 2A=\frac{{}^{}-1-1}{{}^{}-1}$

$\Rightarrow 2A=1-\frac{1}{{}^{}-1}$

$B=\frac{{}^{}-1}{{}^{}-1}$

$\Rightarrow 2B=\frac{2.({}^{}-1)}{{}^{}-1}$