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刚才输错了,1/3十1/(3X5)十1/(5X7)十1/(7x9)十1/(9x11)十1/(11x13)

题目详情
刚才输错了,1/3十1/(3X5)十1/(5X7)十1/(7x9)十1/(9x11)十1/(11x13)
▼优质解答
答案和解析
=1/2×(1-1/3+1/3-1/5+1/5-1/7+17-1/9+1/9-1/11-13分之1)
=1/2×(1-1/13)
=1/2×12/13
=6/13