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(1+1/1x3)x(1+1/2x4)x(1+1/3x5)x(1+1/4x6)x.(1+1/9x11)

题目详情
(1+1/1x3)x(1+1/2x4)x(1+1/3x5)x(1+1/4x6)x.(1+1/9x11)
▼优质解答
答案和解析
[1+1/(1×3)]×[1+1/(2×4)]×[1+1/(3×5)]×[1+1/(4×6)]×.×[1+1/(9×11)]
=[(1×3+1)/(1×3)]×[(2×4+1)/(2×4)]×[(3×5+1)/(3×5)]×[(4×6+1)/(4×6)]×.×[(9×11+1)/(9×11)]
=[(2²)/(1×3)]×[(3²)/(2×4)]×[(4²)/(3×5)]×[(5²)/(4×6)]×.×[(10²)/(9×11)]
=(2²×3²×4²×5²×6²×7²×8²×9²×10²)/[(1×3)×(2×4)×(3×5)×(4×6)×……×(9×11)
=[(2×3×4×5×6×7×8×9×10)²]/(1×2×3×4×5×6×7×8×9×10×11)
=(2×3×4×5×6×7×8×9×10)/11
=3628800/11
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