Logarithmic

1)log₁₁(7x +1) - log₁₁(x - 5)= 1log₁₁[(7x +1)/(x - 5)] = log₁₁11(7x + 1)/(x - 5) = 117x + 1 = 11x - 55x = 14 2)log₄3x - log₄(x - 1) = log₂3log₄[3x/(x- 1)] = log₄3²3x/(x - 1) = 93x = 9x - 9x = 3/2
I HOPE THIS CAN HELP YOU! ^_^

2012-06-19 17:33:50 補充：
3) log₀.₅12x³ - log₀.₅2x - log₀.₅3x³
= log₀.₅{12x³/[(2x)(3x³)]}
= log₀.₅(2/x)
= log₀.₅2 - log₀.₅x
= log₀.₅0.5⁻¹ - log₀.₅x
= - 1 - log₀.₅x
= - 1 - log_(1/2) x

log_11 (7x+1)-log_11 (x-5) =1
=> log_11[(7x+1)/(x-5)]=log_11(11)
=> (7x+1)/(x-5)=11
=> 7x+1=11x-55
=> 4x=56
=> x=14