"One number is nine more than the other"
That means that if one number "x" is nine more than another number, then, the other number must be (x-9).
"Their sum is 33"
Therefore
[tex]x+(x-9)=33[/tex]Solve that for x
[tex]\begin{gathered} 2x-9=33 \\ \\ 2x=33+9 \\ \\ 2x=42 \\ \\ x=21 \end{gathered}[/tex]Therefore, the value of x is 21. Then
[tex]\begin{gathered} 21+(21-9)=33 \\ \\ 21+12=33 \end{gathered}[/tex]The numbers are 21 and 12.