Final answer:
The slope of line AB is negative and the slope of line CD is positive.
Step-by-step explanation:
The slope of a line can be determined by comparing the change in the y-coordinates with the change in the x-coordinates.
If a line is increasing from left to right, it has a positive slope, while if a line is decreasing from left to right, it has a negative slope.
In this case, line AB is decreasing, which means it has a negative slope. Line CD is increasing, which means it has a positive slope.