Posted by ayan on .
What is the sum of all the possible values of a for which 25x2+(a−15)x+9 has exactly one distinct real root?

math 
black_widow,
Let 25x^2+(a−15)x+9=0
Discriminant B^24AC=0 (only one distinct root)
(a15)^24(25)(9)=0
(a15)^2=900
a=15+30 or a=1530
a=45 a=15
therefore sum of a =45+(15)
a =30