log₅ 240-log₅75-log₅ 80=
log₅ (240/75)-log₅ 80= (log_a b- log_a c=log_a (b/c) )
:log₅3.2 - log₅80=
log₅(3.2/80)= (log_a b- log_a c=log_a (b/c) )
log₅0.04=
log₅ 4/100=
log₅ 1/25=
log₅ 1 - log₅ 25= (log_a 1=0)
0-log₅25=
-log₅25=
-log₅5²=x ⇔ x=-2 (log_a a^n=n)
Answer: log₅ 240-log₅75-log₅ 80=-2