I think the equation is y= -x - 4
Step-by-step explanation:
The two given coordinates are (0,-4) and (4,-7).
Use those to find the slope which is -1
Then use the slope intercept form and substitute the answers where they belong.
y - y1 = m(x - x1)
y - (-4) = -1 (x - 0)
y = -x - 4