Let's solve the equation step by step.

The given equation is:
\[ x \times x \times 5 = 36 + 4 \]

First, simplify the right-hand side:
\[ 36 + 4 = 40 \]

So the equation becomes:
\[ x \times x \times 5 = 40 \]

This can be rewritten as:
\[ 5x^2 = 40 \]

Now, divide both sides by 5 to isolate \( x^2 \):
\[ x^2 = \frac{40}{5} \]
\[ x^2 = 8 \]

To solve for \( x \), take the square root of both sides:
\[ x = \sqrt{8} \]
\[ x = \pm \sqrt{8} \]

Since \(\sqrt{8}\) can be simplified further:
\[ \sqrt{8} = \sqrt{4 \times 2} = \sqrt{4} \times \sqrt{2} = 2\sqrt{2} \]

So the solutions are:
\[ x = \pm 2\sqrt{2} \]

Therefore, \( x \) can be \( 2\sqrt{2} \) or \( -2\sqrt{2} \).