Let's solve the equation step by step. The equation you provided is:
\[ 4x^2 + 12x + 9 = (x - 4)^2 \]
First, let's expand the right side:
\[ (x - 4)^2 = x^2 - 8x + 16 \]
Now, substitute this back into the equation:
\[ 4x^2 + 12x + 9 = x^2 - 8x + 16 \]
Now, move all terms to one side of the equation to set it to 0:
\[ 4x^2 + 12x + 9 - x^2 + 8x - 16 = 0 \]
Combine like terms:
\[ (4x^2 - x^2) + (12x + 8x) + (9 - 16) = 0 \]
This simplifies to:
\[ 3x^2 + 20x - 7 = 0 \]
Now, we can use the quadratic formula \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \), where \( a = 3 \), \( b = 20 \), and \( c = -7 \).
Calculating the discriminant (\( b^2 - 4ac \)):
\[ b^2 - 4ac = 20^2 - 4 \cdot 3 \cdot (-7) = 400 + 84 = 484 \]
Now, applying the quadratic formula:
\[ x = \frac{-20 \pm \sqrt{484}}{2 \cdot 3} \]
Calculating \( \sqrt{484} = 22 \):
\[ x = \frac{-20 \pm 22}{6} \]
Now, we find the two solutions:
\( x = \frac{-20 + 22}{6} = \frac{2}{6} = \frac{1}{3} \)
\( x = \frac{-20 - 22}{6} = \frac{-42}{6} = -7 \)
Thus, the solutions to the equation \( 4x^2 + 12x + 9 = (x-4)^2 \) are:
\[ x = \frac{1}{3} \quad \text{and} \quad x = -7 \]