The parabola y = ax^2 + bx + c is graphed below. Find a + b + c. (The grid lines are one unit apart.) The parabola passes through (-2,8), (0,0), and (2,8).
The vertex is (0,0) = (h,k)
Using the vertex form y =a(x -h)^2 + k and (2,8) we can find "a"
8 = a (2 -0)^2 + 0
8 = 4a
a = 8/4 = 2
So
y = 2 (x)^2 + 0
y = 2x^2
a = 2 b = 0 c = 0
a + b + c = 2
+820 
