To solve the equation \((x + 7)^{2} = 81\), we will start by taking the square root of both sides.
\[ x + 7 = \pm 9 \]
This gives us two separate equations to solve:
- \(x + 7 = 9\)
- \(x + 7 = -9\)
Solving the first equation:
\[ x + 7 = 9 \] Subtracting 7 from both sides: \[ x = 9 - 7 \] \[ x = 2 \]
Solving the second equation:
\[ x + 7 = -9 \] Subtracting 7 from both sides: \[ x = -9 - 7 \] \[ x = -16 \]
Thus, the solutions to the equation \((x + 7)^{2} = 81\) are
\[ \boxed{2} \quad \text{and} \quad \boxed{-16}. \]