2/3 + (-5/6) - (-1/2)

Having a hard time understanding this question (see attachment).

Currently, the largest cruise ship has a tonnage of 225,282 gross tons (gt). which of the following is a reasonable estimate for the tonnage of this cruise ship? a. 2 × 10^5 gt b. 2 × 10^6 gt c. 2 × 10^-5 gt d. 2 × 10^-6 gt

The statement tan theta= -12/5, csc theta=-13/12, and the terminal point determained by theta is in quadrant two