Find an equation of the line that satisfies the given conditions

I have three "find the equation of the line" problems I cannot complete correctly.

1.

Through points (-1, -6) and (2, -4)

2.

Through the origin; parallel to the line 3x + 15y = 22

--- on this one, I was able to find the slope. m= -3/15 but I got stuck after that.

3.

Through (-1, -2); perpendicular to the line 2x + 5y + 8 = 0

---I also found the slope for this one: m= 5/2, but again, I got stuck after.

If anyone could help me with these, I would be grateful.

Thanks!