已知a>0，b>0，c>0且a+b+c=1，求 证1/a+1/b+1/c>=9？

解,1/a+1/b+1/c =(a+b+c)/a+(a+b+c)/b+1(a+b+c)/c =1+b/a+c/a+1+a/b+c/b+1+a/c+b/c ≥3+2√(b/axa/b)+2√(