Example 3 (Laws of Logarithms)

Example 3

Given that log 7 4=0.712   and log 7 5=0.827  , evaluate the following.
(a) log 7 20
(b) log 7 1 1 4
(c) log 7 0.8
(d) log 7 28
(e) log 7 140
(f) log 7 100
(g) log 7 0.25
(h) log 7 35 64