(x 2+mx+n)(x-3)=x 3-3x 2+mx 2-3mx+nx-3n=x 3+(m-3)x 2+(n-3m)x-3n,
∵结果中不含x 2、x项,∴m-3=0,n-3m=0,
解得:m=3,n=9.
故答案为:3,9.