Answer:
a = - 2
Step-by-step explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
here (h , k) = (- 2, - 3), hence
y = a(x + 2)² - 3
To find a substitute x = - 1, y = - 5 into the equation
- 5 = a - 3 ⇒ a = - 5 + 3 = - 2
The coefficient of the squared expression is - 2