solve for the unknown:log 5⁡〖1/25〗+log 16⁡4-log(1/3)⁡〖1/9〗=m

log 5⁡〖1/25〗= -2

log 16⁡4 ?? do you mean log 164?
if so, then it has a value of 1/2

log(1/3)⁡〖1/9〗= 2

now you put it all together, once you decide what the middle term is.