Question

solve 0 = 4x²+12x+9.
select the equation that shows the correct
substitution of a, b, and c in the quadratic formula.
○
x = (12 ± √(12² - 4(4)(9))) / (2(4))
○
x = (-12 ± √(12² + 4(4)(9))) / (2(4))
○
x = (-12 ± √(12² - 4(4)(9))) / (2(4))

Explanation:

Step1: Recall Quadratic Formula

The quadratic formula for a quadratic equation \(ax^2 + bx + c = 0\) is \(x=\frac{-b\pm\sqrt{b^2 - 4ac}}{2a}\).

Step2: Identify \(a\), \(b\), \(c\)

For the equation \(4x^2+12x + 9 = 0\), we have \(a = 4\), \(b = 12\), \(c = 9\).

Step3: Substitute into Formula

Substitute \(a = 4\), \(b = 12\), \(c = 9\) into the quadratic formula:
\(x=\frac{-12\pm\sqrt{12^2-4(4)(9)}}{2(4)}\)

Answer:

\(x = \frac{-12\pm\sqrt{12^{2}-4(4)(9)}}{2(4)}\) (the third option)