Question

What is the sum of all the possible values of a for which 25x^2+(a−15)x+9 has exactly one distinct real root?

Answer 1

(5x -3)(5x-3)
25^x^2 -30x +9

I start with the above factors because of the 25 and the 9 and the requirement of one distinct room.

So.. a-15 = -30