y=ax^2+bx+c
25a+5b+c=-14
9a+3b+c=-6
4a+2b+c=1 getting differences...
16a+2b=-8
5a+b=-7 (10a+2b=-14) differences again...
6a=6, so a=1 making 16a+2b=-8 become:
16+2b=-8, so b=-12 making 4a+2b+c=1 become:
4-24+c=1, so c=21 so our quadratic is:
y=x^2-12x+21
