The graph of y = ax^2 + bx + c is shown below. Find abc. (The distance between the grid lines is one unit.)
When x = 0, y = 7 so 7 = a*0^2 + b*0 + c
When x = 3, y = 1, so 1 = a*3^2 + b*3 + c
When x = 6, y = 7, so 7 = a*6^2 + b*6 + c
You now have three simultaneous equations for the three unknowns. I'll leave you to solve them.
Vertex form of parabola with vertex ( 3,1)
y = a ( x-3)^2 + 1 when x = 0 y = 7 then 'a' = 7/10
y = 7/10 (x-3)^2 + 1 expand to find a , b and c
