Answer:
y = - x² - 4x + 13
Explanation:
The equation of a parabola in standard form is
y = ax² + bx + c ( a ≠ 0 )
Given
y = - (x + 2)² + 17 ← expand factor using FOIL
= - (x² + 4x + 4) + 17 ← distribute parenthesis by - 1
= - x² - 4x - 4 + 17 ← collect like terms
y = - x² - 4x + 13