Answer:
The Answer : 19/8 Not sure if I'm correct
Answer:
<h2>16kg</h2>
Step-by-step explanation:
This problem is borers on elasticity of materials.
according to Hooke's law,<em> "provided the elastic limit of an elastic material is not exceeded the the extension e is directly proportional to the applied force."</em>

where F is the applied force in N
k is the spring constant N/m
e is the extension in meters
Given data
mass m= 24kg
extensnion=15cm in meters=
= 
we can solve for the spring constant k
we also know that the force F = mg
assuming 
therefore

We can use this value of k to solve for the mass that will cause an extension of 

It is the third equation: −512⋅(65⋅13)⋅92=(−512⋅65)⋅(13⋅92)
Associative property means one can group the individual operations arbitrarily without changing the result.
Vertex form is

where (h,k) is the vertex.
We can see that the vertex of the graph is at (2,0), and that the graph opens downwards, but does not look stretched at all.
Therefore,
a = -1
h = 2
k = 0
and our vertex form equation is

which is answer A