1/1×2+1/2×3+1/3×4+…+1/2010×2011+1/2012×2013
1/1×2+1/2×3+1/3×4+…+1/2010×2011+1/2012×2013
2013×(1/1×2+1/2×3+1/3×4+……1/+2011×2012+2012×2013)怎么算?
1!×3-2!×4+3!×5…-2010!×2012+2011! ×2013-2012!怎么做?
1-2+3-4+.2009-2010+2011~2012+2013-2014
(-1*2/1)+(-1/2*1/3)+(-1/3*1/4)+…+(-1/2012*1/2013)
1-2+3-4+…+2009-2010+2011+2012
计算出 1×2/1+2×3/1+3×4/1+4×5/1+…………+2010×2011/1+2011×2012/1
(-1×1/2)+(-1/2×1/3)+(1/3×1/4)+…+(-1/2011×1/2012)+(-1/2012×1/
2010 1/2+(-2011 5/6)+(-2012 2/3)+2013 1/3+(-1 1/2)
1/2013+2/2013+3/2013+4/2013+…+2011/2013+2012/2013
|1/2-1|+|1/3-1/2|+|1/4-1/3|+...+|1/2012-1/2011|+|1/2013-1/20
计算:1/1*3+1/2*4+1/3*5+…+1/2011*2013+1/2012*2014