SOLUTION: Find the possible value of k for which the quadratic expression 9x^2-2(k+7)x+k is a perfect square.

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Question 1102740: Find the possible value of k for which the quadratic expression 9x^2-2(k+7)x+k is a perfect square.
Answer by greenestamps(13196) About Me  (Show Source):
You can put this solution on YOUR website!


There are none.

The solutions to the general quadratic equation ax^2+bx+c=0 are given by the quadratic formula:

x+=+%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F2a

For the quadratic expression to be a perfect square, the two roots must be the same; that means b^2-4ac must be zero. In this problem,


But that expression has no real roots.