Mercedes is helmet diving at a location of -20 feet. The breathing tube attached to her helmet reaches an oxygen tank at a location of 12 feet.
Which of the following expressions represents
the length, in feet, of the breathing tube attached
to Mercedes' helmet?
(A) |--20 – 12
(B) |--20 + 12
(C) 20 – 12
(D) -20 + 12