\(\frac{2009\cdot2010-1}{2008\cdot2010+2009}=\frac{2008\cdot2010+2010-1}{2008\cdot2010+2009}=\frac{2008\cdot2010+2009}{2008\cdot2010+2009}=1\)

\(\frac{\left(2008+1\right).2010-1}{2008.2010+2009}=\frac{2008.2010+2010-1}{2008.2010+2009}\)\(=\frac{2008.2010+2009}{2008.2010+2009}=1\)

bằng 1 bạn ạ

bằng 1 bạn ạ

=\(\frac{2010x125+1000}{\left(125+1\right)x2010-1010}=\frac{2010x125+1000}{125x2010+2010-1010}=\frac{2010x125+1000}{2010x125+100}=1\)

k nha bạn

Đề bài yêu cầu gì vậy bạn?

\(A=\frac{2011\times2012}{2011+2012}+\frac{2009\times2010}{2009+2010}\)

\(A=\frac{2011\times2011}{2011+2012}+\frac{2011}{2011+2012}+\frac{2010\times2010}{2009+2010}-\frac{2010}{2009+2010}\)

\(A=\frac{2011\times2011}{2011+2012}+\frac{2010\times2010}{2009+2010}+\frac{2011}{2011+2012}-\frac{2010}{2009+2010}\)

\(A=B+\frac{2011}{2011+2012}-\frac{2010}{2009+2010}\)

\(A=B+\frac{2011}{4023}-\frac{2010}{4019}\)

Dễ thấy \(\frac{2011}{4023}-\frac{2010}{4019}< 0\)

\(\Rightarrow A< B\)

\(\left(\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+....+\frac{1}{2009\cdot2010}\right)\cdot x=2009\)

\(\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{2009}-\frac{1}{2010}\right)\cdot x=2009\)

\(\left(1-\frac{1}{2010}\right)\cdot x=2009\)

\(\frac{2009}{2010}\cdot x=2009\)

\(x=2009:\frac{2009}{2010}\)

\(x=2010\)

\(\left(\frac{1}{1}-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}+....+\frac{1}{2009}-\frac{1}{2010}\right).x=2009\)

\(\left(\frac{1}{1}-\frac{1}{2010}\right).x=2009\)

\(\frac{2009}{2010}.x=2009\)

\(x=2009:\frac{2009}{2010}\)

\(x=2010\)

x = 2010

dễ thật nên tui đố mọi người đó

hihihiihihihi

dễ thì thôi không trả lời nữa

a)|x|<8

=>|x| E {0;1;2;3;4;5;;6;7}

=>x E {0;-1;1-2;2;-3;3;-4;4;-5;5;-6;6;-7;7}

b)2009+[312+(-2009)+(-312)]

=2009+312+(-2009)+(-312)

=[2009+(-2009)]+[312+(-312)]=0+0=0

tick đi

a, \(\frac{1}{2009}+\frac{2}{2009}+...+\frac{2008}{2009}\\ \frac{\left(1+2008\right)\cdot2008\div2}{2009}=\frac{2017036}{2009}\)

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