Odpowiedź :
[tex]a) \\log_327=3\\log_3\frac19=-2\\log_3\sqrt3=\frac12\\\\b) \\log_5125-log_5\frac15=log_5(\frac{125}{\frac15})=log_5(125*5)=log_5625=4[/tex]
[tex]c)\\log_728+log_7\frac{49}4=log_7(28*\frac{49}4)=log_7(7*49)=log_77^3=3[/tex]
Wzory:
[tex]log_ab=c \to a^c=b\\a^{-1}=\frac{1}a\\a^{-n}=\frac{1}{a^n}\\a^{\frac{1}n}=\sqrt[n]a\\a^{\frac{n}{m}}=\sqrt[n]{a^m}\\log_ab+log_ac=log_a(b*c)\\log_ab-log_ac=log_a(\frac{b}c)[/tex]
Odpowiedź:
[tex] log_{3}27 = log_{3} {3}^{3 } = 3 \\ log_{3} \frac{1}{9} = log_{3} {3}^{ - 2} = - 2 \\ log_{3} \sqrt{3} = log_{3} {3}^{ \frac{1}{2} } = \frac{1}{2} [/tex]
[tex] log_{5}125 - log_{5} \frac{1}{5} = log_{5}125 \div \frac{1}{5} = log_{5}625 = log_{5} {5}^{4} = 4 [/tex]
[tex] log_{7}28 + log_{7} \frac{49}{4} = log_{7}(28 \times \frac{49}{4} ) = log_{7}343 = log_{7} {7}^{3} = 3[/tex]