简便运算:3/(2x4)+3/(4x6)+3/(6x8)+```+3/(98x100)要所有的过程 急
2x4+4x6+6x8+.+98x100
1x2+2x4+3x6+4x8 ------------------------------- 2x3+4x6+6x9+
1x2+2x4+3x6+4x8+5x10+.+20x40 简便计算
1x1-2x2+3x3-4x4+5x5-6x6.-100x100+101x101
1X2+2X4+3X6+.50X100
(1x2+2x4+3x6+4x8)/(2x3+4x6+6x9+8x12)
算数题 求解1/1X2+1/2X3+1/3X4+1/4X5+1/5X6+1/7X8要过程
1x2+2x4+3x6+4x8+5x10+.+20x40 怎么算?
1x2/1+2x3/1+3x4/1+.+2009x2010/1=? 2x4/1+4x6/1+6x8/1+.+2010x2
简便计算1/2+1/2x3+1/3x4+1/4x5+...+1/99x100
2x2/1x3+4x4/3x5+6x6/5x7+8x8/7x9+10x10/9x11+12x12/11x13 仔细看看
计算:1/1x2+1/2x3+1/3x4+1/4x5+1/5x6+1/6x7+1/7x8+1/8x9+1/9x10.