Comparing Absolute Values: Are -|-801| and |+801| Opposite Numbers?

To solve this problem, we will evaluate each expression involving absolute value separately and then determine if they are opposites.

• Step 1: Evaluate the absolute value of -801:
  $\left|-801\right| = 801$ because the absolute value is the positive value or magnitude of the number.
• Step 2: Evaluate the absolute value of +801:
  $\left|+801\right| = 801$ since the absolute value of a positive number is the number itself.
• Step 3: Negate the result of the first step:
  $-\left|-801\right| = -801$.
• Step 4: Compare $-801$ and $801$:
  These numbers have the same magnitude (801) but opposite signs.

Therefore, the numbers $-\left|-801\right|$ and $\left|+801\right|$ are indeed opposites.

The correct choice is Yes.