3分之2+15分之2+35分之2+63分之2+99分之2
=2/3+2/15+2/35+2/63+2/99(乘以最小公倍数5*7*9*11=3465)
=2*(5*7*9*11/3+7*9*11/3+9*11+5*11+5*7)/3465
=3150/3465
=630/693
=70/77
=10/11
3分之2+15分之2+35分之2+63分之2+99分之2
=2/3+2/15+2/35+2/63+2/99(乘以最小公倍数5*7*9*11=3465)
=2*(5*7*9*11/3+7*9*11/3+9*11+5*11+5*7)/3465
=3150/3465
=630/693
=70/77
=10/11