Question

Giúp mình vs

Answer 1

Vì B =\(\dfrac{2005^{2015}+1}{2005^{2016}+1}\) < 1

\(\Rightarrow\) B = \(\dfrac{2005^{2015}+1}{2005^{2016}+1}\) <\(\dfrac{2005^{2015}+1+2004}{2005^{2016}+1+2004}\)

\(\Rightarrow\)B = \(\dfrac{2005^{2015}+1}{2005^{2016}+1}\) < \(\dfrac{2005^{2015}+2005}{2005^{2016}+2005}\)

\(\Rightarrow\) B = \(\dfrac{2005^{2015}+1}{2005^{2016}+1}\) < \(\dfrac{2005^{2015}+2005}{2005^{2016}+2005}\)

\(\Rightarrow\) B = \(\dfrac{2005^{2015}+1}{2005^{2016}+1}\) < \(\dfrac{2005\left(2005^{2014}+1\right)}{2005\left(2005^{2015}+1\right)}\)

\(\Rightarrow\) B = \(\dfrac{2005^{2015}+1}{2005^{2016}+1}\) < \(\dfrac{2005^{2014}+1}{2005^{2015}+1}\) = A

Vậy A > B

Answer 2

\(2005A=\dfrac{2005.\left(2005^{2014}+1\right)}{2005^{2015}+1}=\dfrac{2005^{2015}+2005}{2005^{2015}+1}\)

\(2005A=\dfrac{2005^{2015}+1+2004}{2005^{2015}+1}=1+\dfrac{2004}{2005^{2015}+1}\)

\(2005B=\dfrac{2005.\left(2005^{2015}+1\right)}{2005^{2016}+1}=\dfrac{2005^{2016}+2005}{2005^{2016}+1}\)

\(2005B=\dfrac{2005^{2016}+1+2004}{2005^{2016}+1}=1+\dfrac{2004}{2005^{2016}+1}\)

Vì \(\dfrac{2004}{2005^{2015}+1}>\dfrac{2004}{2005^{2016}+1}\Rightarrow1+\dfrac{2004}{2005^{2016}+1}>\dfrac{2004}{2005^{2016}+1}\)

\(\Rightarrow10A>10B\Rightarrow A>B\)

Answer 3

ác bn mách mk cách khác đi