$123456789\times 8+9$ is equal to:

This evaluation follows a distinct, recursive mathematical digit pattern layout:
* $1\times 8+1=9$
* $12\times 8+2=98$
* $123\times 8+3=987$
* $1234\times 8+4=9876$
* $\dots$
* $123456789\times 8+9=987654321$

Hence, the correct computation result matches $987654321$.