1. log₂(-x)=-1/2; (-x)>0;
2^(-1/2)=-x;
1/√2=-x;
x=-1/√2;
2. log√₇(3x-2)=2;(3x-2)>0;
log₇¹/²(3x-2)=2;
2log₇(3x-2)=2;
log₇(3x-2)=1; ⇒ 7¹=(3x-2);
3x=7+2=9;
x=3;
3. -3·log¹/₃(25-x²)=6;(25-x²)>0;
-3·log₃⁻¹(25-x²)=6;
(-3)·(-1)·log₃(25-x²)=6;
log₃(25-x²)=2; ⇒ 3²=(25-x²);
x²=25-9=16;
x₁=+4;x₂=-4;
5.log₄x-log₁₂x=log₁₂ 27;
lgx/lg4-lgx/lg12=lg27/lg12;
lgx·(lg12-lg4)=lg27·lg4·lg12/lg12;
lgx·lg48=lg27·lg4;
lgx=lg27·lg4/lg48;
7.log(₄₋₃x)(2x+3)=1;⇒(4-3x)¹=2x+3;
5x=1;
x=1/5;