To determine which option is equivalent to [tex]\(18 - \sqrt{-25}\)[/tex], we need to work through the expression [tex]\(18 - \sqrt{-25}\)[/tex].
1. Identify the square root of a negative number:
The expression inside the square root is [tex]\(-25\)[/tex]. The square root of a negative number involves imaginary numbers. Recall that [tex]\(\sqrt{-1} = i\)[/tex], where [tex]\(i\)[/tex] is the imaginary unit.
2. Simplify the square root:
[tex]\[
\sqrt{-25} = \sqrt{25 \cdot (-1)} = \sqrt{25} \cdot \sqrt{-1} = 5i
\][/tex]
3. Substitute this back into the original expression:
[tex]\[
18 - \sqrt{-25} = 18 - 5i
\][/tex]
Thus, the expression [tex]\(18 - \sqrt{-25}\)[/tex] simplifies to [tex]\(18 - 5i\)[/tex].
Therefore, the correct answer is:
[tex]\[
\boxed{18 - 5i}
\][/tex]
