A positive altitude gives a distance above sea level. A negative altitude gives a distance below se (a) Find the absolute value of the altitude for each checkpoint. Checkpoint \( \mathrm{A}:|25|=\square \) Checkpoint B: \( |-30|=\square \) (b) Which checkpoint is closer to sea level? Checkpoint A Checkpoint B Neither is closer to sea level.

The absolute value of an altitude is simply the distance from sea level, regardless of whether it's above or below. So for Checkpoint A, the absolute value is \( |25| = 25 \), meaning it’s 25 units above sea level. For Checkpoint B, \( |-30| = 30 \), indicating it’s 30 units below sea level. Now, if we're comparing distances from sea level, Checkpoint A, at 25 units above sea level, is closer to sea level than Checkpoint B, which is 30 units below it. So the answer is Checkpoint A!