Helpppppppp asap please with calculations pls pls pls

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.