15% of what number is 4.20

Step-by-step explanation:

92.8

Step-by-step explanation:

we know that

The vertex form of a quadratic equation is equal to

where

(h,k) is the vertex of the parabola

Let's analyze each case to determine the solution

case a)

in this problem

using a graph tool

see the attached figure N

case b)

in this problem

using a graph tool

see the attached figure N

case c)

in this problem

using a graph tool

see the attached figure N

case d)

in this problem

using a graph tool

see the attached figure N

therefore

the answer is

The equation that has a graph that is a parabola with a vertex at is

case a)