Helpppppppp asap please with calculations pls pls pls

Answer:
For the first one it is y = -5x because for it to be direct it can't have a b-intercept. it must start at 0.
Second question: y2 - y1/x2 - x1
13-(-8)/(-4)-3
21/(-7)
-3 is the slope
y= -3x + b
13 = -3(-4) + b
13 = 12 + b
12 - 13 = b
b = -1
y=-3x-1
0 = -3x - 1
1 = -3x
1/-3 = -3x/-3
x= -1/3
y=-3x-1
y=-3(0)-1
y= -1
The answer to the 3rd question is y = 1x + 2 because the rise over run is one and the line crosses the y-intercept at 2.
I am not sure if these answers are correct.