To solve logarithmic equations it will be useful for you to remember these basic properties of logarithms:
To solve a basic logarithmic equation, only rewrite the equation in exponential form and solve for the variable.
Solve: log2512 = -3x+9
512 = 2-3x+9 <=> 29= 2-3x+9 <=> 9=-3x+9 <=> 3x = 0 <=> x = 0
Solve: log4(5x+6) = 4
5x+6=44 <=> 5x+6=256 <=> 5x=250 <=> x=50