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