how to make a dns server that uses dhcp for ip addresses and still work with pcs on a diffrent router interface$($ i want the dhcp done by the router and $2$ dns servers one is www$.$a$.$com, anther www$.$b$.$com$)($pls$,$ i need the commands i have an exam tommrow i cant do it$)$

$1)$ router gi$0/1$ we will assign ip dhcp pool using router$($i know houw to that $)/$make deaflt gatway

$2)$same thing for servers

but no matter what i do i get host name un resloved