If the quadratic expression `x^(2) + (a-4)x + (a+4)` is a perfect square, then `a = "______"`.

Options

A. 0 and -4
B. 0 and 6
C. 0 and 12
D. 6 and 12

Answer

C

Explanation

(i) If the equation is a perfect square, then it has equal roots.
(ii) Quadratic equation is a perfet square, if `b^(2) - 4 ac = 0`
(ii) Quadratic equation is a perfect square, if `b^(2) - 4 ac = 0`.
(ii) Substitute the value of b and c in the above eqution and obtained the value of a.