To solve the equation \( x^2 = 100 \), you need to find the values of \( x \) that satisfy this equation.

1. Take the square root of both sides of the equation:
\[
\sqrt{x^2} = \sqrt{100}
\]

2. Simplify both sides:
\[
x = \pm 10
\]

So, the solutions to the equation \( x^2 = 100 \) are:
\[
x = 10 \quad \text{or} \quad x = -10
\]