Find the Discriminant 12x=-4x^2-9

$12 x = - 4 x^{2} - 9$

Move all the expressions to the left side of the equation.

Add $4 x^{2}$ to both sides of the equation.

$12 x + 4 x^{2} = - 9$

Add $9$ to both sides of the equation.

$12 x + 4 x^{2} + 9 = 0$

The discriminant of a quadratic is the expression inside the radical of the quadratic formula.

$b^{2} - 4 (a c)$

Substitute in the values of $a$ , $b$ , and $c$ .

$12^{2} - 4 (4 \cdot 9)$

Evaluate the result to find the discriminant.

Simplify each term.

Raise $12$ to the power of $2$ .

$144 - 4 (4 \cdot 9)$

Multiply $4$ by $9$ .

$144 - 4 \cdot 36$

Multiply $- 4$ by $36$ .

$144 - 144$

Subtract $144$ from $144$ .

$0$