To solve the equation \( x^2 = 100 \), you can take the square root of both sides. This yields:
\[ x = \pm \sqrt{100} \]
Calculating the square root, we have:
\[ x = \pm 10 \]
Thus, the solutions to the equation are:
\[ x = 10 \quad \text{and} \quad x = -10 \]