That can be done. Assuming that the public IP is "pub" and IP addresses of two servers in dmz are "web" & "ftp", you need to implement following commands-
static (dmz,outside) tcp pub 21 ftp 21
static (dmz,outside) tcp pub 80 ftp 80
access-list outin permit tcp any host pub 21
access-list outin permit tcp any host pub 80
access-group outin in interface outside
** Replace "pub", "web" & 'ftp" with respective IP addresses.