Two numbers multiply to -50 and add up to -10

There is a line with slope 1/a going through the point (a, a²). find the equation of the line perpendicular to this line at this point. (don’t let this problem intimidate you! solve the problem as you would if i’d given you specific values. just use variables instead.)

This is about circle theorems. someone asap : (

Rewrite 9 log, x2 in a form that does not use exponents. 9log, x = log, x