3)log(3)x≤4
x>0 U x≤81
x∈(0;81]
4)log(4)(7-x)<3<br>7-x>0 U 7-x<64<br>x<7 U x>-57
x∈(-57;7)
5)y=lg(x²-7)
x²-7x>0
x(x-7)>0
x=0 x=7
x∈(-∞;0) U (7;∞)
6)log(3)(2x-1)<3<br>2x-1>0 U 2x-1<27<br>2x>1 U 2x<28<br>x>1/2 U x<14<br>x∈(1/2;14)
7)
8)(3log(7)2-log(7)24):(log*7)3+log(7)9)=log(7)[8/24]:log(7)27=
=log(7)1/3:log(7)27=log(27)1/3=-1/3