Y=mx+b 
M=Slope
B= y-intercept 
Your m=-1/4 because you’re going 1 down and 4 right 
B=0 because it’s is at the center which is 0
From your B (0) you go 1 down and 4 to the right. Always know your b so you can know what your slope is. 
And your slope is a negative