设a=357240,b=456312
则题目为比较
(a+6)/(b+9)与a/b的大小
(a+6)/(b+9)-a/b
=(ab+6b-ab-9a)/(b(b+9))=(2b-3a)*(3/((b(b+9))))
易知2b-3a=2*456312-3*357240