Answer:
<h2>
k = 3</h2>
Step-by-step explanation:
The vertex is (d, e)
for quadratic function: f(x) = ax² + bx + c we have:
d = -b/a and d = (x₁ + x₂)/2
a = 1, b = k, x₁ = -4, x₂=-2
so:
d = -b/a = -k/1 = -k and d = (x₁ + x₂)/2 = (-4-2)/2 = -3
-k = -3
k = 3
Answer:

Step-by-step explanation:
The formula for the area of a circle is : 
To work this out you would first have to work out the area of the circle. You can do this by multiplying pi by 8 squared, this gives you 201.06. This is because in order to calculate the volume you must calculate the area of one face of the shape.
The next step is to multiply 201.06 by 10, this gives you 2010.62.
1) Multiply pi by 8 squared.

2) Multiply 201.06 by 10.

Answer:
see below
Step-by-step explanation:
amount of water w
l liter of pure alcohol = 100% alcohol
solution is 45 % percent alcohol
total amount of fluid is w+l
(w+l)( .45) = l*.100
Distribute
.45w + .45 l = 1l
.45 w = 1l - .45l
.45 w = .55l
w = .55l / .45
w =11/9 l
Using the definition of vertical angles, the value of z is: 15.
<h3>Vertical Angles Pair</h3>
The two pairs of opposite angles formed when two straight lines intersect are called vertical angles, and are therefore congruent to each other.
Thus:
2z + 10 = 40
2z = 40 - 10
2z = 30
z = 30/2
z = 15
Therefore, using the definition of vertical angles, the value of z is: 15.
Learn more about vertical angles on:
brainly.com/question/1673457
Alrighty, so, without the picture and the clues given I'm going to assume the image you have looks like two angles coming from the middle of a straight line. A straight line is equal to 180 degrees. 180 degrees minus 168 degrees equals 12.