Các câu hỏi tương tự
1×2×3+2×3×3+3×3×4+.....+2011×2012×3+2012×2013×3
TÍNH NHANH ;
A= 1*2+2*3+3*4+....+2011*2012
B =2012*2013+2013*2014
A=[2012+2011/2+2010/3+2009/4+...1/2012]:[1/2+1/3+1/4+...+1/2012+1/2013]
HOI A CHIA 3 DU BAO NHIEU ?
Hãy chứng minh A = B , biết:
A = 1 + (1+ 2) + (1+ 2+ 3) + ...........+ ( 1+ 2+ 3+ 4+ ...+ 2013)
B = 2013 x 1 + 2012 x 2 + 2011 x 3 + ......+ 2 x 2012 + 1 x 2013
\(choA=\frac{2012+\frac{2011}{2}+\frac{2010}{3}+\frac{2009}{4}+...+\frac{1}{2012}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2012}+\frac{1}{2013}}.hỏiAchia3dưbaonhiêu\)
Tính hợp lý (2011/2012+2012/2013+2013/2014+2014/2015)×(1/5-2/3:10/3)
A có chia hết cho 3 không?
\(A=\frac{2012+\frac{2011}{2}+\frac{2010}{3}+\frac{2009}{4}+...+\frac{1}{2012}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2012}+\frac{1}{2013}}\)
\(A=\frac{2012+\frac{2011}{2}+\frac{2010}{3}+\frac{2009}{4}+...+\frac{1}{2012}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2012}+\frac{1}{2013}}\)
hỏi A có chia hết cho 3 hay ko ?
CMR 2011/2012 + 2012/2013 +2013/2011 >3