(1/5+1/7+1/9+1/11)*(1/7+1/9+1/11+1/13)-(1/5+1/7+1/9+1/11+1/1

来源：学生作业帮编辑：大师作文网作业帮分类：数学作业时间：2024/11/12 14:08:53

(1/5+1/7+1/9+1/11)*(1/7+1/9+1/11+1/13)-(1/5+1/7+1/9+1/11+1/13)*(1/7+1/9+1/11)
简便运算

提取=(1/5+1/7+1/9+1/11)*(1/7+1/9+1/11)+(1/5+1/7+1/9+1/11)*1/13-(1/5+1/7+1/9+1/11)*(1/7+1/9+1/11)-1/13*(1/7+1/9+1/11)=(1/5+1/7+1/9+1/11)*1/13-1/13*(1/7+1/9+1/11)=1/13*(1/5+1/7+1/9+1/11-1/7+1/9+1/11）=1/13*1/5=1/65

(1/5+1/7+1/9+1/11)*(1/7+1/9+1/11+1/13)-(1/5+1/7+1/9+1/11+1/1 (5/1+7/1+9/1+11/1)*(7/1+9/1+11/1+13/1)-(5/1+7/1+9/1+11/1+13/ 计算:（1/5+1/9+1/11）*（1/7+1/9+1/11+1/13）-（1/5+1/7+1/9+1/11+1/13 计算:1/3*5+1/5*7+1/7*9+1/9*11+1/11*13 1/5*7+1/7*9+1/9*11+1/11*13+.+1/23*25 一道奥数题,简算（1/5+1/7+1/9+1/11）×（1/7+1/9+1/11+1/13）—（1/5+1/7+1/9+ 计算：2/3*5+1/5*7+1/7*9+1/9*11+1/11*13 1×3/1+3×5/1+5×7/1+7×9/1+9×11/1+11×13/1简便运算 (1/3+1/5+1/7+1/9)*(1/5+1/7+1/9+1/11)-(1/3+1/11+1/5+1/7+1/9)* 简便计算1/1*3*5+1/3*5*7+1/5*7*9+1/7*9*11+1/9*11*13+1/11*13*15中1/ 1/3+1/5+1/7+1/9+1/11+1/13+1/15= 1/5*7+1/7*9+1/9*11+1/11*13