log 2x log 4x log 128 log 2x log 4x log 128 log 2x log

Solution

log 2x + log 4x =log 128

=> log ( 2x * 4x ) = log 128

=> 2x * 4x = 128 [ remove log in both sides ]

=> 8x^2 = 128

=> x^2 = 16

=> x = 4 ( answer )