巧算 三道(2x4x6x8x10+1x3x5x7x9)/(1x2x3x4x5)(10x9x8x7x6-5x4x3x2x1) / ( 3x4x5x6x)(1x2x3x4x5x6+6x7x8x9x10x11) / (1x2x3x4x5x6) 数学
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【答案】 (2x4x6x8x10+1x3x5x7x9)/(1x2x3x4x5)
解,得:
==[2(1*2*3*4*5)+1*3*5*7*9)]/(1*2*3*4*5)
==[2(1*2*3*4*5)/(1*2*3*4*5)]+[(1*3*5*7*9)/(1*2*3*4*5)]
==2+(63/8)
==9.875
(10x9x8x7x6-5x4x3x2x1) / ( 3x4x5x6x)
解,得:
==
(1x2x3x4x5x6+6x7x8x9x10x11) / (1x2x3x4x5x6)
解,得:
==[(1x2x3x4x5x6)/(1x2x3x4x5x6)]+[(6x7x8x9x10x11)/(1x2x3x4x5x6)]
==1+462
==463