Which situation has a net result of zero? The temperature was -9'F and fell 9°F.
Janet had $4 and gave $3 to her friend.
High tide was 5.5 ft and now low tide is -0.5 ft.
The hot-air balloon rose 539 feet. It then lost 539 feet of altitude.

The bottom of ignacio's desktop is 74.5cm from the floor. ignacios sits in his adjustable chair, and the tops of his legs are 49.3cm from the floor. each clockwise rotation of the knob on the chair raises ignacio's legs by 4.8cm. write an inequality to determine the number of clockwise rotations, r, ignacio could make with the knob without his legs touching the desk.