9ˣ - 3ˣ⁺¹ +8/9 = 0
9ˣ⁺¹ - 3ˣ⁺³ + 8 = 0
3²ˣ⁺² - 9ₓ3ˣ⁺¹ + 8 = 0
3ˣ⁺¹ = y y² - 9y + 8 = 0 y² - y - 8y +8 = 0 y(y-1) - 8(y-1) = 0 (y-1)(y-8) = 0
y - 1 = 0 y = 1 3ˣ⁺¹ = 3⁰ x+1 = 0 x = -1
y - 8 = 0 y = 8 3ˣ⁺¹ = 2³ (x+1)lg3 = 3lg2 x + 1 = 3lg2 /lg3 = 3ₓ0,2/0,477
x = 1 = 1,257 x = 0,257
