Под буквами а и б помогите пожалуйстааа)))))))))))))

A) $lgx+1=t, \frac{1}{t} + \frac{6}{t+4} =1, t+4+6t=t(t+4), 7t+4=t^2+4t,$
$t^2-3t-4=0, (t-4)(t+1)=0, t=4,t=-1$
1. $lgx+1=4, lgx=3, x= 10^{3}=1000$
2. $lgx+1=-1, lgx=-2, x=10^{-2}= \frac{1}{100}$
b) $log_2 \frac{x}{4}= \frac{15}{log_2 \frac{x}{8}-1 }, log_2 \frac{x}{4}= \frac{15}{log_2 \frac{x}{4}-log_22-1 },log_2 \frac{x}{4}= \frac{15}{log_2 \frac{x}{4}-2 },$
$log_2 \frac{x}{4}-2=t,t+2= \frac{15}{t}, t^2+2t-15=0,(t+5)(t-3)=0,$ $t=3,t=-5$
1. $log_2 \frac{x}{4}-2=3, log_2 \frac{x}{4}=5, \frac{x}{4}=2^5, x=4*2^5=128$
2. $log_2 \frac{x}{4}-2=-5, log_2 \frac{x}{4}=-3, \frac{x}{4}=2^{-3}, x= \frac{1}{2}$