Find a function from points

I don't need the answer, just some help with setting it up! :)

Curve fitting: find the function y=ax^2+bx+c whose graph contains the points (1, 2), (-2, -7), and (2, -3).

all in all, they want you to set up a system of three equations and three unknown a,b and c

since y=ax²+bx+c

for(1,2)
2= a+b=c

for (-2,-7)
-7= 4a -2b +c
and for (2,-3)
-3 = 4a +2b+c

I think you can find a,b and c from here.