Question 1180493
Slope will need to be  {{{-1/3}}}.


Using point-slope equation form,  you want {{{y+5=-(1/3)(x-9)}}}.


Simple algebra:
{{{-3y-15=x-9}}}
{{{-15+9=x+3y}}}
{{{x+3y=-6}}}
{{{highlight(x+3y+6=0)}}}