Answer:
"a" must be negative
Step-by-step explanation:
The slope between points (-1, 1) and (1, -1) is a minimum of (-1-1)/(1-(-1)) = -1.
The slope between points (1, -1 and (3, -4) is a maximum of (-4-(-1))/(3-1) = -3/2.
Thus, as x increases, the slope is decreasing. In order for that to be the case, the value of a must satisfy a < 0.
