А)lg^2x-2lg x =3б)log по основанию 3 x - log по основанию x 9=1помогиииииите

1)(lgx)^2 - 2lgx = 3
замена lgx=t
t^2 - 2t - 3 = 0
D=4+12=16
t1=(2+4)/2=3
t2=(2-4)/2=-1
lgx1=3 lgx2=-1
x1=1000 x2=1/10
2) $log_{3}x - log_{x}9=1 \\\\ \frac{1}{log_{x}3} - 2log_{x}3=1\\\\ log_{x}3 = t\\\\ \frac{1}{t} - 2t -1 = 0|*t\\\\ -2t^{2}-1t+1=0\\\\ 2t^{2}+t-1=0\\\\ D=1+8=9\\\\ t1=(-1+3)/4=1/2\\\\ t2=(-1-3)/4=-1\\\\ log_{x1}3 = 1/2\\\\ x1=9\\\\ log_{2}3 = -1\\\\ x2=1/3$