A. When you add to negative numbers, it is always negative. A positive + a positive is positive. In D, the answer is always 0. 1 + -1 is 0. In C, it varies. The bigger number not including the negative sign is the sign the number has. For example, -6 + 5 = -1. 6 is bigger than 5. You subtract the smaller number from the bigger number and that is the answer. You would then tack on the negative sign because it is -6, and 6 is bigger than 5.
Step-by-step explanation:
Go 2.5 units to the right from the origin (0,0) for your x coordinate
Go 2.5 units down from the origin (0,0) for your y coordinate
Where the lines meet is your point.
The solution to this equation is 1=2