We use logarithm properties/identities to simplify the equation. One of the properties of logarithms is
[tex] log_{a}b = logb/loga [/tex]
Applying this property:
x=log[2](1/128)
x = log(1/128) / log 2
Use your calculator to determine each logarithms
x = -2.11 / 0.301
x = -7