y=(log_{10}(15))/(log_{10)(4)}

解

y = \frac{lo g _{10} ( 15 )}{lo g _{10} ( 4 )}

y = lo g_{4} (15)

十進法表記

y = 1.95344 \dots

解答ステップ

y = \frac{lo g _{10} ( 15 )}{lo g _{10} ( 4 )}

対数の規則を適用する:

\frac{lo g _{c} ( b )}{lo g _{c} ( a )} = lo g_{a} (b)

\frac{lo g _{10} ( 15 )}{lo g _{10} ( 4 )} = lo g_{4} (15)

y = lo g_{4} (15)