let
A (-4,35)
B (-3,20)
C (-2,10)
D (-1,5)
E (0,8)
F (1,10)
G (2,15)
H (3,30)
I (4,48)
using a graph tool
case a) y=2.23x²+1.62x+5.26
see the attached figure N 1
case b) y=4.63x²+0.84x+4.14
see the attached figure N 2
case c) y=0.98x²+3.06x+6.02
see the attached figure N 3
case d) y=3.72x²+2.94x+3.21
see the attached figure N 4
using a Quadratic Regression Calculator
the Best Fit Second-Degree Quadratic Regression is
2.228x²+1.617x+5.255
see the attached figure N 5
therefore
the answer is
case a) y=2.23x²+1.62x+5.26
