It would be y=1(x+1)^2-4
The vertex, which is the midpoint, is (-1, -4), making h = -1 and k = -4.
By the way, since this uses the vertex form/equation, you need an A-value (y=a(x-h)+k).
The easiest way you could find the a-value is by getting one of the x-intercepts and putting it in as x and y. For this question, I used (1, 0), meaning that x is 1 and y is 0 (even if you used the other x-intercept, which is (-3, 0), you should get the same answer as me).
0 = a (1 + 1)^2 - 4
0 = a (2)^2 - 4
0 = 4a - 4
4 = 4a
a = 1
We should get the same value for a using the other x-intercept.
0 = a (-3+1)^2 - 4
0 = a (-2)^2 - 4
0 = 4a - 4
4 = 4a
a = 1