For this question you will use point slope form.
The formula is: y-y1=m(x-x1)
y1 and x1 are points on the graph
Plug in (3,-4) this is (x1,y1)
y+4 = m(x-3)
we must find m by plugging in a different point
(0,5)
9 = -3m move -3 to the other side
m = -3
y+4=-3(x-3) would be your answer
D
