Answer:
Option B. The equation has a maximum value with a y-coordinate of -21.
Step-by-step explanation:
The correct quadratic equation is

This is a vertical parabola open downward (the leading coefficient is negative)
The vertex represent a maximum
Convert to vertex form
Factor -3

Complete the square


Rewrite as perfect squares

The vertex is the point (2,-21)
therefore
The equation has a maximum value with a y-coordinate of -21
Answer:
5000kg/m3
Step-by-step explanation:
Its easy to get the answer of a question from the unit.
So, it will be mass over metre cube.
Therefore, m=40kg x= (0. 2)^3 =0. 008m
40/0. 008 = 5000kg/m^3
R2+15r+36=0 the answer is r=6