Как решать? Помогите пжл help

[latex]1) log_{49}7= \frac{log_{7}7}{log_{7}49} = \frac{1}{2} \\ 2)log_27-log_263+log_236= log_2 \frac{7}{63}+log_236=log_2( \frac{7*36}{63} )=2 \\ 4)log_{ \frac{1}{3} }log_327=log_{ \frac{1}{3} }3= \frac{1}{log_3 \frac{1}{3} } =-1 \\ 5)25^{2-log_575}= \frac{25^2}{25^{log_575}}= \frac{625}{5^{2log_575}}= \frac{625}{5^{2*log_525*3}}= \frac{625}{5^{2*(log_525+log_53)}} = (*) [/latex] [latex](*)= \frac{625}{5^{4+2log_53}}= \frac{625}{5^4*5^{2log_53}}= \frac{625}{5^4*3^2}= \frac{1}{9} [/latex]