Question

log in baza 11 din 11 + log in baza 7 din 1 supra 7 ?

Answer 1

$\log_{11} 11+ \log_7 \frac{1}{7} = \\ \\ \log_{11}11=1 \\\\ \log_7 \frac{1}{7} = \frac{\log_{11 \frac{1}{7} }}{\log_{11}7} =- 1 \\ 1-1=0$

Answer 2

$\displaystyle log_{11}11+log_7 \frac{1}{7}=1+log_7 \frac{1}{7} =1-log_77=1-1=0$