Answer:
The equation has a maximum value with a y-coordinate of -21.
Step-by-step explanation:
Given

Required
The true statement about the extreme value
First, write out the leading coefficient

means that the function would be a downward parabola;
Downward parabola always have their vertex on top of the parabola and as such, the function has a maximum value.
The maximum value is:

Where:

So, we have:



Substitute
in 


<em>Hence, the maximum is -21.</em>
Answer:
independent
Step-by-step explanation:
Dependent equations graph as the <em>same line</em>. These lines are not the same, so the equations are independent.
___
However, the lines are parallel, so the equations are also <em>inconsistent</em>. There is <em>no solution</em> to this system of equations.
Answer:
5 should be subtracted from each term
Step-by-step explanation:

Cross multiply,
1 * (11 - x) = 2*(8-x)
11 -x = 2*8 - 2*x
11 - x = 16 - 2x
Subtract 11 from both sides,
-x = 16 - 2x - 11
-x = 5 - 2x
Add 2x to both sides
-x +2x = 5 - 2 + 2x
x = 5
{1,2,3,4,5,6,7,8}= Sample space