Question 1148046
points (3,6) and (4,b)
Slope is  {{{(b-6)}}}.


points (a,0) and (-5,b)
Slope is {{{b/(-5-a)}}}


The first described line of your description has slope of  {{{(-5-2)/(3-a)}}}, or  {{{-7/(3-a)}}}.


Description gives equations, {{{system(-7/(3-a)=b-6,and,(-7/(3-a))(b/(-5-a))=-1)}}}.
Simplify and solve the system.