Cho a = log53; b = log7

Câu hỏi: Cho a = log₅3; b = log₇5 . Tính log₁₅105 theo a và b.

A. ${\log }_{15}\left(105\right)=\frac{1+\mathrm{a}+\mathrm{ab}}{(1+\mathrm{a})\mathrm{b}}$

B. ${\log }_{15}\left(105\right)=\frac{1+\mathrm{b}+\mathrm{ab}}{1+\mathrm{a}}$

C. ${\log }_{15}\left(105\right)=\frac{\mathrm{a}+\mathrm{b}+1}{\mathrm{b}(1+\mathrm{a})}$

D. ${\log }_{15}\left(105\right)=\frac{1+\mathrm{b}+\mathrm{ab}}{(1+\mathrm{a})\mathrm{b}}$