<h2><u>Given</u> :</h2>
The given equations are :


Let's solve for g in equation (2) :


now, let's plug value of g from equation (3) into equation (1) :





plugging value of b in equation (3) :



since " g " represents ground seats, number of ground seats :
=》396
And " b " represents balcony seat, therefore it is equal to :
=》312

Using it's vertex, the maximum value of the quadratic function is -3.19.
<h3>What is the vertex of a quadratic equation?</h3>
A quadratic equation is modeled by:

The vertex is given by:

In which:
Considering the coefficient a, we have that:
- If a < 0, the vertex is a maximum point.
- If a > 0, the vertex is a minimum point.
In this problem, the equation is:
y + 4 = -x² + 1.8x
In standard format:
y = -x² + 1.8x - 4.
The coefficients are a = -1 < 0, b = 1.8, c = -4, hence the maximum value is:

More can be learned about the vertex of a quadratic function at brainly.com/question/24737967
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Answer:
x = -1
Step-by-step explanation:
By graphing x = -1, you will see that the line splits this rhombus in two equal halves
That does not make sense sorry :(