Answer:
b = 6
Step-by-step explanation:
f(x) = -x^2+bx+c
A(-1,0) => f(-1) = 0 => -1-b+c =0 =>c-b=1 (1)
B(3,16) => f(3) = 16 => -9+3b+c = 16=>c+3b=25 (2)
Subtract (2) to (1) => 4b = 24 => b = 6 => c = b + 1 = 6 + 1 = 7
y = -x² + bx + c
h = -b/(2×-1) = b/2
h = 3
b/2 = 3
b = 3×2
