Evaluate: 2 log 5 + log 8 – log 4

We know that: n log a = log (aⁿ)

2 log 5 = log (5)²= log 25 and

log 4 = log (4)^1/2 = log 2

2 log 5 + log 8 – log 4 = log 25 + log 8 – log 2

Using Formula: log a + log b = log (ab)

log a – log b = log ()

log 25 + log 8 – log 2 = log ( = log 100

2 log 5 + log 8 – log 4 = log 100 = 2 log 10

We know that: log 10 = 1

So,

2 log 5 + log 8 – log 4 = 2 × 1 = 2