2/5*7+2/7*9+2/9*11+2/11*13+2/13*15+2/15*17=??? Решите пример

Question

2/5*7+2/7*9+2/9*11+2/11*13+2/13*15+2/15*17=???
Решите пример

Answer 1

14/5+18/7+22/9+26/11+30/13+34/15.
1) 14/5+34/15=42/15+34/15=76/15.
2) 18/7+22/9=(18*9+22*7)/63=316/63.
3) 26/11+30/13=(26*13+30*11)/143=668/143.
4) 76/15+316/63=(76*63+316*15)/945=9528/945.
5) 9528/945+668/143=(9528*143+668*945)/(945*143)=1993764/135135=14 101874/135135
Ответ; 14 целых 101874/135135