Answer:
see explanation
Step-by-step explanation:
The standard form of a quadratic is
ax² + bx + c = 0 : a ≠ 0
Given
y = (2x + 3)² = (2x + 3)(2x + 3) ← expand factors
= 2x(2x + 3) + 3(2x + 3)
= 4x² + 6x + 6x + 9 ← collect like terms
= 4x² + 12x + 9 ← in standard form, hence
0 = 4x² + 12x + 9 ← standard quadratic equation
with a = 4, b = 12 and c = 9
