作业帮(1+1/2+1/3+1/4+1/5)*(1/3+1/4+1)-(1+1/3+1/4)*(1/2+1/3+1/4+1/5)
来源：学生作业帮助网 编辑：作业帮 时间：2024/04/29 13:11:17
(1+1/2+1/3+1/4+1/5)*(1/3+1/4+1)-(1+1/3+1/4)*(1/2+1/3+1/4+1/5)
(1+1/2+1/3+1/4+1/5)*(1/3+1/4+1)-(1+1/3+1/4)*(1/2+1/3+1/4+1/5)
(1+1/2+1/3+1/4+1/5)*(1/3+1/4+1)-(1+1/3+1/4)*(1/2+1/3+1/4+1/5)
设 1/2+1/3+1/4+1/5 = A
(1+1/3+1/4) = B
(1+1/2+1/3+1/4+1/5)*(1/3+1/4+1)-(1+1/3+1/4)*(1/2+1/3+1/4+1/5)
= 1 * B + A * B - B * A
= 1 * B
= (1+1/3+1/4)
= 19/12
原式=(1+1/3+1/4)*(1+1/2+1/3+1/4+1/5-1/2-1/3-1/4)=19/12*1=19/12
(1+1/2+1/3+1/4+1/5)*(1/3+1/4+1)-(1+1/3+1/4)*(1/2+1/3+1/4+1/5)
＝1*(1/3+1/4+1)＋（1/2+1/3+1/4+1/5)*(1/3+1/4+1)-(1+1/3+1/4)*(1/2+1/3+1/4+1/5)
＝1*(1/3+1/4+1)
＝7/12＋1
＝19/12
19/12