Look at the picture.
The slope-intercept form: y = mx + b
m - slope
b - y-intercept
We have:
[tex]b=-4[/tex]
[tex]m=\dfrac{\Delta y}{\Delta x}\to m=\dfrac{+1}{+1}=1[/tex]
Substitute:
[tex]y=1x-4=x-4[/tex]
