1)(2/3)^(x+5)=(2/3)^(1-3x), x+5=1-3x, 4x=-4,x= -1
2)2^x *3^x=36, (2*3)^x=6^2,
6^x=6^2, x=2
3)2^(x^2 -9)=1, x^2 -9=0,
(x-3)(x+3)=0, x=3, x= -3
4)5^(2-x)<125=5^3, (2-x)<3, x> -1
5)(1/3)^(x^2-4x+3)>=3^(1-x^2),
3^(-x^2+4x-3)>=3^(1-x^2),
-x^2+4x-3>=1-x^2, 4x>=4, x>=1