实际上是(1+1/2)*(1+1/3)*(1+1/4)***(1+1/9)=(3/2)*(4/3)*(5/4)***(10/9)=5
前一个因式的分子可以跟后一个因式的分母约去
原式=(1+2分之1)*(1+3分之1)*(1+4分之1)*........(1+9分之1)
=3/2*4/3*5/4*.....10/9
=10/2=5
(1+1/2) × (1+1/4) × (1+1/6) × (1+1/8) × (1+1/3) × (1+1/5) × (1+1/7) × (1+1/9)
= 3/2 × 5/4 × 7/6× 9/8 × 4/3 × 6/5 × 8/7 × 10/9
=5