jika 3log5=a dan 2log3=b, maka nilai dari 18 log45 adalah

[tex]^3log5=a \\
^2log3=b \\
^{18} log45 = \frac{^3log45}{^3log18} \\ = \frac{^3log( {3}^{2} \times 5) }{^3log( {3}^{2} \times 2 )} \\ = \frac{^3log{3}^{2} + ^3log5}{^3log {3}^{2} +^3log2 } \\ = \frac{2 + a}{2 + \frac{1}{b} } \times \frac{b}{b} \\ = \frac{2b + ab}{2b + 1} [/tex]