Convert the logarithmic equation into exponential form. The statement log_2(x + 6) = 3 means x + 6 = 2^3. Now calculate 2^3 = 8, so x + 6 = 8. Subtract 6 from both sides: x = 8 - 6 = 2. Finally, check the domain: x + 6 must be positive, and 2 + 6 = 8 > 0, so the answer is valid.