ab/(a+b)=2 bc/(b+c)=3 ac/(a+c)=5 a=?b=?c=?

问题描述:

ab/(a+b)=2 bc/(b+c)=3 ac/(a+c)=5 a=?b=?c=?

ab/(a+b)=2 bc/(b+c)=3 ac/(a+c)=5 取倒数得:(a+b)/ab=1/2(b+c)/bc=1/3(a+c)/ac=1/5即:1/a+1/b=1/2 (1)1/b+1/c=1/3 (2)1/a+1/c=1/5 (3)(1)加(2)加(3)式得:(1/a+1/b+1/c)=[(1/2)+(1/3)+(1/5)]/2...