!) (1/2)^3х-1=16^-2
2^(-3x+1)=2^-8
-3x+1=-8
x=3
2) (4/5)^1-2х=1,25^3
(4/5)^1-2x=(5/4)^3
(5/4)^-1+2x=(5/4)^3
-2+2x=3
x=2.5