Question 178427
the vertex is on the axis of symmetry


the general equation for the axis of symmetry is x = -b/(2a)


in this case, 10=-b/(2*20)


multiplying by 40 __ 400=-b  __  -400=b


the value of c can be found by substituting the vertex coordinates


-3=20(10^2)-400(10)+c  __  -3=2000-4000+c


adding 2000 __  1997=c