If you would like to solve (- 0.5) / (- 0.5) and - 50 / (- 0.5), you can do this using the following few steps:
(- 0.5) / (- 0.5) = 0.5 / 0.5 = 1
- 50 / (- 0.5) = 50 / 0.5 = 50 / (5/10) = 50 / (1/2) = 50 * 2/1 = 100
The correct results would be: (- 0.5) / (- 0.5) = 1 and - 50 / (- 0.5) = 100.