For this case the first thing you should know is that we have an equation of the form:
y = mx + b
Where,
m: slope of the line
b: cutting point with the vertical axis.
For this case, we observe that the values of y decrease when the values of x increase.
Therefore, the function decreases.
This means that it is true that:
m <0
Therefore, the slope of the line is negative.
Answer:
A word that describes the slope of the line is:
negative