$\Leftrightarrow\ \log\ 0,75\ =\ \log\left(\frac{75}{100}\right)$

Gunakan sifat logaritma $^{c\ }\log\left(\frac{a}{b}\right)\ =\ ^c\log\ a\ -^c\log b$

$\Leftrightarrow\log\left(\frac{75}{100}\right)$

$\Leftrightarrow\log75\ -\ \log\ 100$

$\Leftrightarrow\log\left(3\times5\times5\right)\ -\ \log\ 100$

Gunakan sifat logaritma $^a\log\ b\times c=\ ^a\log\ b+^a\log\ c$

$\Leftrightarrow\log3+\log\ 5+\log5\ -\ \log\ 100$

$\Leftrightarrow\log3+\log\ 5+\log5\ -\ \log\ 10^2$

Gunakan sifat logaritma $^{a^m}\log b^n=\frac{n}{m}\times^a\log b$ dan $\log\ 10\ =1$

$\Leftrightarrow\log3+\log\ 5+\log5\ -2\times\ \log\ 10^{ }$

$\Leftrightarrow\log3+\log\ 5+\log5\ -2\times1$

Substitusi nilai yang diketahui dari soal

$\Leftrightarrow0,3862+0,5741+0,5741-2=-0,4656$