To solve the equation \( -x^{3/2} = -27 \), we can first eliminate the negative sign by multiplying both sides by -1:
\[ x^{3/2} = 27 \]
Next, we can solve for \( x \) by raising both sides to the power of \( \frac{2}{3} \):
\[ x = 27^{\frac{2}{3}} \]
Calculating \( 27^{\frac{2}{3}} \):
- Find the cube root of 27, which is 3.
- Then square that result: \( 3^2 = 9 \).
Thus, \( x = 9 \).
Therefore, the correct answer is:
9