tính ttir số a/b
a=1/2+1/3+1/4+...........+1/2007+1/2008+1/2009
b=2008/1+2007/1+2006/1+......2/2007+1/2008
Những câu hỏi liên quan
Tính tỉ số B A , biết: 2008 1 2007 2 ... 3 2006 2 2007 1 2008 2009 1 2008 1 2007 1 ... 4 1 3 1 2 1 = + + + + + = + + + + + + B A
Tính tỉ số A/B biết:
A=1/2+1/3+1/4+...+1/2007+1/2008+1/2009
B=2008/1+2007/2+2006/3+...+2/2007+1/2008
*A/B là phân số.
1/2 +1/3+1/4 .... +1/2007 +1/2008
2008/1 =2007/2 + 2006/3 ... + 2/2007 + 1/2008
Tính tỉ số a/b, biết :
A=1/2+1/3+1/4+1/5+.....+1/2008+1/2009
B=2008/1+2007/2+2006/3+....+2/2007+1/2008
Tính tỉ số a/b, biết :
A=1/2+1/3+1/4+1/5+.....+1/2008+1/2009
B=2008/1+2007/2+2006/3+....+2/2007+1/2008
giải dùm mk với. chiều ni mk thi học kì. bài cuối sợ là bài này lắm
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tính nhanh
A=2008+2007/2+2006/3+2005/4+…..+2/2007+1/2008
1/2+1/3+1/4+1/5+…..+1/2007+1/2008
A=2008+2007/2+2006/3+2005/4+...+2/2007+1/2008
1/2+1/3+1/4+1/5+...+1/2007+1/2008
=(1+2007/2)+(1+2006/3)+(1+2005/4)+...+(1+2/2007)+(1+1/2008)
1/2+1/3+1/4+...+1/2008
=2009(1/2+1/3+1/4+...+1/2008)
1/2+1/3+1/4+..+1/2008
=2009
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Tính A/ B biết
A= 2008+ 2007/2 + 2006/3 + 2005/4+....+ 2/2007+ 1/2008 ; B = 1/2+1/3+1/4+1/5+....1/2008+1/2009
A=2008+2007/2+2006/3+2005/4+......+2/2007+1/2008 tất cả trên 1/2+1/3+1/4+1/5+......+1/2008+1/2009
\(B=2008+\frac{2007}{2}+\frac{2006}{3}+\frac{2005}{4}+...+\frac{2}{2007}+\frac{1}{2008}\)
\(=1+1+\frac{2007}{2}+1+\frac{2006}{3}+...+1+\frac{1}{2008}\)
\(=\frac{2009}{2009}+\frac{2009}{2}+\frac{2009}{3}+...+\frac{2009}{2008}\)
\(=2009\left(\frac{1}{2}+\frac{1}{3}+...+\frac{1}{2008}+\frac{1}{2009}\right)\)
Suy ra \(A=2009\).
So sánh
bài 1 :A= 2006/2007-2007/2008+2008/2009-2009/2010
B= -1/2006*2007-1/2008*2009
bài 2: C= 2006/2007+2007/2008+2008/2009+2009/2006 với 4