Perpendicular line always have slopes that are negative reciprocals of one another. Mathematically,
m1*m2=-1
So to be perpendicular to the line given, let's rearrange it to the point slope form of a line...
3y=6x ?3 (not sure what you wanted to type there)
anyway isolating y by dividing both side by three will leave 2x where 2 is the slope.
So for the other line to be perpendicular, m*2=-1, m=-1/2, now we have:
y=-x/2 +b, we can now you the point given to solve for b
4=-2/2 +b
4=-1+b
b=5 so
y=-x/2 +5 or more neatly
y=(10-x)/2
