Solve: Finding the Opposite of Absolute Value -|-18|

The problem requires us to evaluate the expression $-\left|-18\right|$.

Step 1: Calculate the absolute value of $-18$.

• The absolute value of a number is the positive version of the number if it's negative. Therefore:
• $\left|-18\right| = 18$

Step 2: Apply the negative sign to the result of the absolute value operation.

• We attach the negative sign that is outside the absolute value:
• $-\left|-18\right| = -18$

Therefore, the result of the expression $-\left|-18\right|$ is $-18$.