1)log(2)(x-7)=6
x-7=64
x=64+7=73
2)log(3+x)=5
x+3=32
x=32-3=29
3)log(5)(1+x)=log(5)4
1+x=4
x=4-1=3
4)log(4)(x+8)=log(4)(5x-4)
x+8>0 U 5x-4>0⇒x>-8 U x>0,8⇒x>0,8
4+8=5x-4
5x-x=8+4
4x=12
x=3
5)log(1/8)(13-x)=-2
13-x=64
x=13-64=-51
6)log(2)(11-x)=4log(2)5
11-x>0⇒x<11<br>log(2)(11-x)=log(2)625
11-x=625
x=11-625=-614
7)log(3)(x²+4x)=lg(3)(x²+4)
x²+4x=x²+4
4x=4
x=1
8)log(4)(5-x)=log(4)(2-x)+1
5-x>0 U 2-x>0⇒x<5 U x<2⇒x<2<br>log(4)(5-x)=log(4)4(2-x)
5-x=8-4x
-x+4x=8-5
3x=3
x=1
9)log(x+1)49=2
x+1>0 U x+1≠1⇒x>-1 U x≠0⇒x∈(-1;0) U (0;∞)
(x+1)²=49
x²+2x+1-49=0
x²+2x-48=0
x1+x2=-2 U x1*x2=-48
x1=-8∉(-1;0) U (0;∞)
x2=6
Не ставь так много,а то поставят нарушение