(1/3)^x+2+5*(1/3)^x+1-(1/3)^x< 7

(1/3)ˣ⁺²+5*(1/3)ˣ⁺¹-(1/3)ˣ<7
(1/3)²*(1/3)ˣ+(5/3)*(1/3)ˣ-(1/3)ˣ<7
(1/9)*(1/3)ˣ+(2/3)*(1/3)ˣ<7
(7/9)*(1/3)ˣ<7   |÷7
(1/9)*(1/3)ˣ<1
(1/3)ˣ<9
(1/3)ˣ<(1/3)⁻²
x>-2
ответ: x∈(-2;+∞).