log5 180 − log5 75 − log5 60
1. Use the fact that logbx - logby = logb(x/y)
log5180 - log575 - log560 = log5(1/25) → log5(25-1) → log5(5-2)
2. Now use the fact that logb(bm) = m
log5(5-2) = -2
So log5180 - log575 - log560 = -2
.
The exact value is -2.