3/(1X4)+3/(4X7)+3/(7X10)+3/(10X13)+3/(13X16)
3/(1X4)+3/(4X7)+3/(7X10)+3/(10X13)+3/(13X16)
1/1x4+1/4x7+1/7x10+1/10x13+1/13X16 简便
计算:1x4分之一+4x7分之一+7x10分之一+10x13分之一+13x16分之一
1/1X4+1/4X7+1/7X10+1/10X13+1/13X16(简算)
2x2/1x3+4x4/3x5+6x6/5x7+8x8/7x9+10x10/9x11+12x12/11x13 仔细看看
100x( 3/1x4 + 3/4x7 +3/7x10 +.3/97x100)=?注:1x4、4x7、7x10等均为分母
1/(1x4)+1/(4x7)+1/(7x10)+1/(10x13)简便运算 找规律 急
1X4分之1十4X7分之1十7X10分之1十10X13分之1简算
lim[1/(1x4)+1/(4x7)+1/(7x10)+...+1/(3n-2)x(3n+1)]=_____
计算①1x2/1+2x3/1+3x4/1+```+19x20/1= ②1x4/1+4x7/1+7x10/1+```+91
数学趣味知识园开幕H1.1X4/1+4X7/1+7X10/1+10X13/1+.+97X100/1 2.1X2X3/1+
计算:1/1x2+1/2x3+1/3x4+1/4x5+1/5x6+1/6x7+1/7x8+1/8x9+1/9x10.