Question

Вычислите наиболее рациональным способом:

Answer 1

1/2*2/3*3/4*4/5*5/6*6/7*7/8=(1/2*2/3)*(3/4*4/5)(5/6*6/7)*7/8=1/3*3/5*5/7*7/8=
=(1/3*3/5)(5/7*7/8)=1/5*5/8=1/8

13/12*11/10*9/8*7/6*6/7*8/7*10/9*12/11=(13/12*12/11)*(11/10*10/9)*(9/8*8/7)*
*(7/6*6/7)=13/11*11/9*9/7*1=13/9*9/7*1=13/7=1.6/7