The graph of a certain quadratic y=ax^2+bx+c is a parabola with vertex (-4,0) which passes through the point \((1,-7)\). What is the value of a?
(-4,0) is a root ....so.....
If we shifted this parabola to the right by 4 units the vertex is (0,0) and we would get rid of the bx and c terms
And now..... ( 1 + 4, -7) becomes (5 , -7)
So
y= ax^2
-7 = a (5)^2
-7 = 25a
a = -7 / 25
