1.2010+2.2009+3.2008+...+2010.1 / [(1+2+3+...+2010)+(1+2+3+...+2009)+...+(1+2)+1]
Tính : 1.2010+2.2009+3.2008+.........+2010.1/(1+2+3 +.....+2010)+(1+2+3+........+2009)+.......(1+2)+1
Tính :
1.2010+2.2009+3.2008+.....+2010.1/(1+2+3+...+2010)+(1+2+3+....+2009)+....+(1+2)+1
\(\dfrac{1.2010+2.2009+.............+2010.1}{\left(1+2+3+......+2010\right)+\left(1+2+3+....+2009\right)+....+\left(1+2\right)+1}\)
\(=\dfrac{1.2010+2.2009+...........+2010.1}{\left(1+1+....+1\right)+\left(2+2+...+2\right)+......+\left(2009+2009\right)+2010}\)
\(=\dfrac{1.2010+2.2009+..........+2010.1}{1.2010+2.2009+..........+2010.1}\)
\(=1\)
Tính:
\(\dfrac{1.2010+2.2009+3.2008+...+2010.1}{\left(1+2+3+...+2010\right)+\left(1+2+3+...+2009\right)+...\left(1+2\right)+1}\)
\(=\dfrac{1\cdot2010+2\cdot2009+3\cdot2008+...+2010\cdot1}{\left(1+1+...+1\right)+\left(2+2+...+2\right)+.....+\left(2009+2009\right)+2010}\\ =\dfrac{1\cdot2010+2\cdot2009+3\cdot2008+...+2010\cdot1}{1\cdot2010+2\cdot2009+3\cdot2008+...+2010\cdot1}\\ =1\)
1.2010 + 2.2009 + 3.2008 + ... + 2010.1
( 1 + 2 + 3 + ... + 2010 ) + ( 1+ 2 + 3 + ... + 2009 ) + ... + ( 1 + 2 ) +1
Giúp mik nha bài này khó quá!
A=1.2010+2.2009+3.2008+...........+2010.1
Tính
1.2010 + 2.2009 + 3.2008 + ... + 2010.1
( 1 + 2 + 3 + ... + 2010 ) + ( 1+ 2 + 3 + ... + 2009 ) + ... + ( 1 + 2 ) +1
Giúp mik nha bài này khó quá, mik ko lm đc là bị phạt đó! :)
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CMR: A= 3/1.2^2+5/2^2.3^2+...+4019/2010^2.2009^2<1
a) 2010/1+2009/2+2008/3+ ... +1/2010+2010 : 1+1/2+1/3+ ... +1/2010=
b) 1/2011+1/2010+1/2009+ ... +1/3+1/2 : 2010/1+2009/2+2008/3+ ... +1/2010=