To solve the quadratic equation \((x + 3)^2 = 36\) using square roots, we start by taking the square root of both sides:
\[ x + 3 = \pm 6 \]
This gives us two equations to solve:
- \(x + 3 = 6\)
- \(x + 3 = -6\)
Now we solve each equation individually.
For the first equation: \[ x + 3 = 6 \] Subtract 3 from both sides: \[ x = 6 - 3 \] \[ x = 3 \]
For the second equation: \[ x + 3 = -6 \] Subtract 3 from both sides: \[ x = -6 - 3 \] \[ x = -9 \]
Thus, the solutions to the equation \((x + 3)^2 = 36\) are: \[ x = 3 \quad \text{and} \quad x = -9 \]