Question

3*(1/9)^x-28*(1/3)^x+9=0

Answer 1

3*(1/9)^x-28*(1/3)^x+9=0
(1/3)^x=t
3t2-28t+9=0
t12=(28+-корень(784-108))/6=(28+-26)/6=1/3 9
(1/3)^x=1/3
x=1
(1/3)^x=9
(3)^(-x)=3^2
x=-2