Answer:
a. y + 3 = 0
Step-by-step explanation:
x-axis has slope of 0 so any lines parallel to x-axis has slope of 0
With m = 0 , x = -4, y = -3
y = mx + b
-3 = (0)(-4) + b
b = -3
so y = -3
or y + 3 = 0