To solve the quadratic equation \((x−4)^2=25\) using square roots, we start by taking the square root of both sides:
\[ x - 4 = \pm 5 \]
This gives us two separate equations to solve:
- \(x - 4 = 5\)
- \(x - 4 = -5\)
Now, solving these equations:
For the first equation:
\[ x - 4 = 5 \] Adding 4 to both sides: \[ x = 5 + 4 = 9 \]
For the second equation:
\[ x - 4 = -5 \] Adding 4 to both sides: \[ x = -5 + 4 = -1 \]
So, the solutions are: \[ x = 9 \quad \text{and} \quad x = -1 \]
Thus, the answer is \({-1, 9}\).