Use the slope formula or rise over run to determine the slope of line A.

Format: m=-5/6

y = (-1/3)x + 4

Step-by-step explanation:

m = rise/run =    y2 - y1         3 - 4        -1

                            =   =

                          x2 - x1          3 - 0       3

y = mx + b

y = (-1/3)x + b

Pick either coordinate. For this, I'll pick (0, 4)

4 = (-1/3)(0) + b

4 = b

y = (-1/3)x + 4

If you are certain about M = (-5/6), then replace (-1/3) with (-5/6)

I hope this helps!