Answer:
12
Step-by-step explanation:
Hello, as the coefficient of the leading term is negative we know that the vertex of the parabola is a maximum. So we need to find the vertex.
This expression is maximum for
[tex]t=-\dfrac{b}{2a} \text{ where the parabola equation is}\\\\ax^2+bx+c=0[/tex]
So, here, it gives t = 8/2=4, and then, the maximum is
[tex]-4^2+8*4-4=-16+32-4=32-20=12[/tex]
So the answer is 12.
Thanks