Mohon bantuanyaaaaaa

[tex]\displaystyle 2^{a+1}=6\\2\cdot2^a=6\\2^a=3\\a={^2\log3}\\\\^2\log15={^2\log(3\cdot5)}\\^2\log15={^2\log 3}+{^2\log5}\\^2\log15={^2\log 3}+\frac{^3\log5}{^3\log2}\\^2\log15=a+\frac{b}{\frac1a}\\^2\log15=a+ab\\\boxed{\boxed{^2\log15=a(b+1)}}[/tex]