((3^x)+3)/4=3/3^(x-2)
3^x=t t > 0 3^(x-2)=3^x*3^(-2)=3^x/3^2=3^x/9=t/9 (t+3)/4=3/(t/9) (t+3)/4=27/t t*(t+3)=4*27 t^2+3t-108=0 D=9+432=441=21^2 t1=(-3+21)/2=9 или t2 < 0 ( не удовл. усл. t > 0) 3^x=9 x=2