To solve the radical equation \( \sqrt{12 + x^4 - 10} = 8 \), the first step would be to isolate the radical.
- We can simplify the radical first: \( \sqrt{12 + x^4 - 10} \) simplifies to \( \sqrt{x^4 + 2} \).
The equation now looks like this:
\[ \sqrt{x^4 + 2} = 8 \]
Next, raise both sides to the second power to eliminate the square root:
\[ x^4 + 2 = 64 \]
Since the option indicated raising both sides to the second power is the first step to eliminating the radical, the correct response here is:
Raise both sides of the equation to the second power.