1/1*3+1/1*3*5+1/1*3*5*7+1/1*3*5*7*9-73/945
问题描述:
1/1*3+1/1*3*5+1/1*3*5*7+1/1*3*5*7*9-73/945
答
原式=(5*7*9+7*9+9+1)/(1*3*5*7*9)-(8*9+1)/(3*3*3*5*7)
=(5*7*9+8*9+1)/(3*5*7*9)-(8*9+1)/(3*5*7*9)
=(5*7*9)/(3*5*7*9)
=1/3