1,1/16,( ),1/256,1/625,请问( )内是那个啊.答案是1/81,我现在想问的是,点计出来的啊.

1,1/16,,1/256,1/625 1,16,81,256,625,《 》 (x-1/2)(2x+1)(2x^2+1/2)(4x^4+1/4)(16x^6+1/16)/(256x^16-1/256) (x-1/2)(2x+1)(2x^2+1/2)(4x^4+1/4)(16x^6+1/16)/(256x^16+1/256)=? (2+1)(4+1)(16+1)(256+1)怎么算? 1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256 1/2-1/4-1/8-16/1-32/1-64/1-128/1-256/1 （1+1/2)(1+1/4）（1+1/16)(1+1/256) 等于多少?快 1/2-1/4-1/8-1/16-1/32-1/64-1/128-1/256 （1+1/2)(1+1/4）（1+1/16)(1+1/256) 等于多少? 1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256 初一(1+1/2)(1+1/4)(1+1/16)(1+1/256)(1-1/2)*(1+1/2)*(1+1/4)*(1+1/16))*(1+1/256)/(1-1/2)=(1-1/256*1/256)/(1-1/2)=2-2/256*256 34+17+8 1/2+7 1/4+6 1/8+5 1/16+4 1/32+3 1/64+2 1/128+1 1/256= 计算：1/2+1/4+1/8+1/16+1/64+1/128+1/256 1-1/2-1/4-1/8-1/16-1/32-.1/256 利用平方差公式计算：（1+1/2)×（1+1/4)×(1+1/16)×（1/256) 1+1/2+1/4+1/8+1/16+1/32.+1/256 ? 简便计算1/2+1/4+1/8+1/16+.+1/128+1/256