Question 14299
To find the slope of a perpendicular line, you take the negative recipricol of the current slope.  
So, the slope of the perpendicular line would be {{{-1/8}}}
Then to solve, you plug in numbers into the {{{y=mx+b}}} equation using the point they gave you (3,4) to solve for b (y-intercept).
{{{4=-1/8*(3)+b}}}
{{{4=-3/8+b}}}
Add {{{3/8}}} to both sides
{{{35/8=b}}}
Then put that back into the equation. 
{{{y=-1/8x+35/8}}}