Hint: This must be a perfect square -- in the form (a + b)^2 or (a - b)^2.
Consider both the cases.
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?
3 answers
45
solutions are
a-15=30 i.e a=45
a-15=-30 i.e a=-15
therefore, answer is 30
a-15=30 i.e a=45
a-15=-30 i.e a=-15
therefore, answer is 30
1 answer