Question 971546
Perpendicular lines have slope products =-1

The slope of the line desired is 2/3, and it goes through (3,9)

Use point-slope formula

Y-y1=m(x-x1)

Y-9 =2/3 (x-3)

Y-9=(2/3)x - 2

Y=(2/3)x + 7

{{{graph(300,300,-10,10,-10,10,-(3/2)x + 4,(2/3)x+7)}}}