1/1X3+1/3X5+1/5X7...1/17X19+1/19X21=
1/1X3+1/3X5+1/5X7...1/17X19+1/19X21=
2/1X3+2/3X5+2/5x7+.+2/19x21
(2X2)/1X3+(4X4)/(3X5)+(6X6)/(5X7)+...+(20X20)/(19X21)==?
2/1X3+2/3X5+2/5x7+.+2/19x21全过程(最好带原因),
1/1x3+1/3x5+1/5x7+1/7x9+1/9x11=?
1/1x3+1/3x5+1/5x7+.+1/2009x2011=
2/1x3+2/3X5+2/5x7=2/7x9+2/9x11
x8+x7+x6+x5+x4+x3+x2+x+1因式分解
1/1x3+1/3x5+1/5x7.1/2009x2010+1/2011x2013
计算:1/1x3+1/3x5+1/5x7+...1/2009x2011+1/2011×2013
1/1x3+1/3x5+1/5x7+……+1/99x101
1/1x3+1/3x5+1/5x7+…+1/2011x2013是多少?