Log3x=log3 1,5+log3 8
log(3)x=log(3)(1,5*8)=log(3)12
x=12
Log7 x=log7 12-log7 3
log(7)x=log(7)(12:3)=log(7)4
x=4
Log0.3 x= 2 log0,3 6-log0,3 12
log(0,3)x=log(0,3)(6²:12)=log(0,3)3
x=3
Log2(x^2+4x+3) =3
x²+4x+3>0
x1+x2=-4 U x1*x2=3⇒x=-3 U x=-1
x∈(-∞;-3) U (-1;∞)
x²+4x+3=8
x²+4x-5=0
x1+x2=-4 U x1*x2=-5
x1=-5
x2=1
Ответ x={-5;1}