Question

Perpendicular to y = 3x + 4 through (0, -2)

Answer 1

If a line is perpendicular, is has a negative reciprocal slope
The slope for the new line will be -1/3x 
To find b, plug in what you know
-2=-1/3(0)=b
-2=b
Now you have everything that you need
your line is y= -1/3x  - 2
Hope this helps!