QUADRATIC-5

If zx² + 12x + 4 = 0 is a perfect square, find the value of z .

Solution

In zx² + 12x + 4 = 0;   a=z, b=12 and c=4.

For the perfect square, b² = 4ac

(12)² = 4 x z x 4

144 = 16z

144 =  16z

 16       16

9 = z

Hence the value of z is 9