So sánh \(\frac{10^{2009}+1}{10^{2010}+1}\frac{10^{2010}+1}{10^{2011}+1}\)
So sánh: P=\(\frac{10^{2010}-1}{10^{2011}-1}\) và Q=\(\frac{10^{2009}-1}{10^{2010}-1}\)
\(P=\dfrac{10^{2010}-1}{10^{2011}-1}\)
\(\Rightarrow10P=\dfrac{10\left(10^{2010}-1\right)}{10^{2011}-1}=\dfrac{10^{2011}-10}{10^{2011}-1}=\dfrac{10^{2011}-1-9}{10^{2011}-1}=1-\dfrac{9}{10^{2011}-1}\)
\(Q=\dfrac{10^{2009}-1}{10^{2010}-1}\)
\(\Rightarrow10Q=\dfrac{10\left(10^{2009}-1\right)}{10^{2010}-1}=\dfrac{10^{2010}-10}{10^{2010}-1}=\dfrac{10^{2010}-1-9}{10^{2010}-1}=1-\dfrac{9}{10^{2010}-1}\)Mà\(\dfrac{9}{10^{2011}-1}< \dfrac{9}{10^{2010}-1}\)
\(\Rightarrow1-\dfrac{9}{10^{2011}-1}>1-\dfrac{9}{10^{2010}-1}\)
Hay \(10P>10Q\Rightarrow P>Q\)
So sánh:
a) M=\(\frac{1999^{1999+1}}{1999^{2000}+1}và\)N=\(\frac{1999^{1989}+1}{1999^{2009}+1}\)
b) A=\(\frac{-9}{10^{2010}}+\frac{-19}{10^{2011}}và\)B=\(\frac{-9}{10^{2011}}+\frac{-19}{10^{2010}}\)
so sánh
a)\(A=\dfrac{-2015}{2015.2016}\) và \(B=\dfrac{-2014}{2014.2015}\) b)A = \(\dfrac{10^{2009}+1}{10^{2010}+1}\) và \(B=\dfrac{10^{2010}+1}{10^{2011}+1}\)
A=-2015/2015x2016
A=-1/2016
B=-2014/2014x2015
B=-1/2015
vi 2016>2015,-1/2016>-1/2015
vay A>B
b) Ta có: \(A=\dfrac{10^{2009}+1}{10^{2010}+1}\)
\(\Leftrightarrow10A=\dfrac{10^{2010}+10}{10^{2010}+1}=1+\dfrac{9}{10^{2010}+1}\)
Ta có: \(B=\dfrac{10^{2010}+1}{10^{2011}+1}\)
\(\Leftrightarrow10B=\dfrac{10^{2011}+10}{10^{2011}+1}=1+\dfrac{9}{10^{2011}+1}\)
Ta có: \(10^{2010}+1< 10^{2011}+1\)
\(\Leftrightarrow\dfrac{9}{10^{2010}+1}>\dfrac{9}{10^{2011}+1}\)
\(\Leftrightarrow\dfrac{9}{10^{2010}+1}+1>\dfrac{9}{10^{2011}+1}+1\)
\(\Leftrightarrow10A>10B\)
hay A>B
Bài 1: So sánh:
A = \(\frac{10^{1992}+1}{10^{1991}+1}\) và B = \(\frac{10^{1993}+1}{10^{1992}+1}\)
C = \(\frac{2010^{2008}+1}{2010^{2009}+1}\) và C = \(\frac{2010^{2007}+1}{2010^{2008}+1}\)
So sánh A và B,biết:
A=\(\frac{10^{2010}+1}{10^{2011}+1}\) và B=\(\frac{10^{2011}+1}{10^{2012}+1}\)
Vì \(\frac{10^{2011}+1}{10^{2012}+1}< 1\)
=> \(B=\frac{10^{2011}+1}{10^{2012}+1}< \frac{10^{2011}+1+9}{10^{2012}+1+9}=\frac{10^{2011}+10}{10^{2012}+10}=\frac{10\left(10^{2010}+1\right)}{10\left(10^{2011}+1\right)}=\frac{10^{2010}+1}{10^{2011}+1}=A\)
Vậy A > B
so sánh $A=\frac{-9}{10^{2010}}+\frac{-19}{10^{2011}}$ và $B=\frac{-9}{10^{2011}}+\frac{-19}{10^{2010}}$
Giải phương trình
\(\frac{1}{2}\left(\frac{2x-2}{2009}+\frac{2x}{2010}+\frac{2x+2}{2011}\right)=\frac{33}{10}-\left(\frac{x+1}{2011}+\frac{x-1}{2009}+\frac{x}{2010}\right)\)
\(A=\frac{2010^{10}-1}{2010^{11}-1}\) \(B=\frac{2010^{10}+1}{2011^{11}+1}\) so sánh A và B
\(A=\frac{2010^{10}-1}{2010^{11}-1}
ko quy đồng hãy so sánh \(A=\frac{-5}{10^{2009}}+\frac{-17}{10^{2010}}vàB=\frac{-17}{10^{2009}}+\frac{-5}{10^{2010}}\)
cu lay phep tinh nay tru phep tinh kia hk ra thi nt hoi mink