对于正整数a.b.c(a小于等于b小于等于c)和实数x.y.z若a^x=b^y=c^z=30^w---<1>1/x+1/y+1/z=1/w---<2>

设a^x=b^y=c^z=30^w=k 则 x=log（a,k）y=log(b,k) z=log(c,k) w=log(30,k) 1/x+1/y+1/z=1/log(a,k)+1/log(b,k)+1/log(c,k)=log(k,a)+log(k,b)+log(k,c)=1/log(30,k)=log(k,30） 所以log(k,abc)=log(k,30) abc=30 又因为a<=b<=c 都为正整数 2.3.5（a,