V15/(V(1//3)+V(1/5))
=V15*V15/(V5+V3)
=15/2 (V5-V3)介绍能在详细些吗 我会追加分数的V15/[V(1/3)+V(1/5)]=V15/(V3/3+V5/5)=V15/(5V3/15+3V5/15)=15V15/(5V3+3V5)=15V15*(5V3-3V5)/[(5V3-3V5)*(5v3+3V5)]=15[V15*(5V3-3V5)]/(75-45)=15/2 *(15V5-15V3)=225/2(V5-V3)