The equation

Question

perpendicular to the line 9x + y = -89; contains the point (-9,-9)

Answer 1

Although you have not so stated, presumably you want the equation of the perpendicular line.

 

The slope of the perpendicular is 1/9.

 

The equation is 1/9 =  (y + 9)/(x + 9).

 

Cross multiply and collect to get the answer is a more familiar form.