Ответ:

-1

Объяснение:

log4(0,8)=log4(4/5)=log4(4)-log4(5)=1-log4(5)

log(5/4)4=1/(log4(5)-log4(4))=1/(log4(5)-1)

log1.25(4)*log4(0,8)=[1/(log4(5)-1)]*[1-log4(5)]=-1