Answer:
f(x) =4x² + x - 7
Step-by-step explanation:
f(x) = ax² + bx + c
f(1) = a + b + c
f(-3) = 9a - 3b + c
f(3) = 9a + 3b + c
a + b + c = -2 -----(1)
c = -2-a-b -----(2)
9a - 3b + c = 26 ------(3)
9a + 3b + c = 32 -------(4)
(2)->(3)
9a-3b-2-a-b = 26
8a-4b = 28
4(2a-b) = 28
2a-b = 7 ----(5)
(2)->(4)
9a+3b-2-a-b = 32
8a+2b = 34
2(4a+b) = 34
4a+b = 17 ----(6)
(5)+(6)
6a = 24
a = 4
sub a=4 into(6)
4(4)+b = 17
b = 1
sub a=4,b=1 into (2)
c = -2-4-1
c = -7
