LOGARITHMS B6

Evaluate Log₂(128 x 32).

Solution

= Log₂(128 x 32)

= Log₂128 +  Log₂32          (applying the product rule)

= Log₂2⁷ +  Log₂2⁵             ( 128= 2⁷ and 32=2⁵ )

= 7Log₂2 +  5Log₂2       ( remember  Log_aa^c = cLog_aa )

= (7 x 1) +  (5 x 1)          ( remember  Log_aa = 1 )

= 7 + 5

= 12

hence Log₂(128 x 32) = 12