Tentukan nilai 4^log15

4 log 15 = 2² log 15 = 1/2 . 2 log 15 = 1/2 (2 log 3 + 2 log 5)
= 1/2(x+2 log 3 . 3 log 5)
= 1/2(x+xy) = 1/2x(1+y)

[tex]^2log3=x \\ ^3log5=y \\ ^4log15=^{2^2}log(5.3) \\ = \frac{1}{2} (^2log(5.3)) \\ = \frac{1}{2} (^2log5+^2log3) \\ = \frac{1}{2} ( \frac{^3log5}{^3log2} +^2log3) \\ = \frac{1}{2} ( \frac{y}{ \frac{1}{x} } +x) \\ = \frac{1}{2} xy+\frac{1}{2}x \\ =\frac{1}{2}x(y+1)[/tex]