(1-3⼀2x4)x(1-3/3X5)x(l一3/4X6)X……X(1-3/7X9)

2024-11-25 05:30:12
推荐回答(2个)
回答(1):

原式=(1x5)/(2x4)x(2x6)/(3x5)x(3x7)/(4x6)x(4x8)/(5x7)x(5x9)/(6x8)x(6x10)/(7x9)
=(1X2X3X4X5X6)X(5X6X7X8X9X10)/[(2X3X4X5X6X7)X(4X5X6X7X8X9)]
=(2X3X4X5X6X7X8X9)X(5X6X10)/[(2X3X4X5X6X7X8X9)X(4X5X6X7)]
=5X6X10/(4X5X6X7)=10/(4X7)=5/14

回答(2):

可不可以把题拍个图片再发。。。