Answer:

Step-by-step explanation:
Given;
x² - 2x - 1 = 0
Solve by completing the square method;
⇒ take the constant to the right hand side of the equation.
x² - 2x = 1
⇒ take half of coefficient of x = ¹/₂ x -2 = -1
⇒ square half of coefficient of x and add it to the both sides of the equation


⇒ take the square root of both sides;

Therefore, option B is the right solution.
Answer:
21 windows
Step-by-step explanation:
collen family plans to paint the windows of their house. her father will paint twice as many windows as her mother, and collen and her 2 brothers will paint an equal number of the rest of the windows. Colleen decided to do her own share and her mother's share and paints 7 window, which is one less than her father's share. how many windows are in their house?
Answer: Let the number of window Collen father would paint be a while that of her mother be b. Since her father will paint twice as many window as her mother, therefore the number of windows painted by the father a = 2b
Let the number of windows that would be needed to be painted each by Colleen and her 2 brothers be c because they would paint the equal number of windows.
The total number of windows to be painted = 2b + b + c + c + c = 3b + 3c = 3(b + c).
Collen painted 7 windows as her mother and her own share which is one less than the fathers share. Therefore b + c = 7.
Also the fathers share a = 2b = 7 + 1 = 8 windows. Therefore b = 4 which is the mother share
Therefore the total number of windows = 3(b + c) = 3(7) = 21 windows
3b + 3c = 21
3(4) + 3c = 21
12 + 3c = 21
3c = 21 - 12
3c = 9
c = 3 which is collen and her brothers share
The probability notation for choosing a red disk is P(red disk)
<h3>How to determine the notation?</h3>
From the question, we have the following highlights:
- The scenario represents probability
- The event is choosing a red flask
Probability notations are represented as:
P(Event)
Since the event is choosing a red flask, the probability would be
P(red disk)
Hence, the probability notation for choosing a red disk is P(red disk)
Read more about probability at:
brainly.com/question/251701
#SPJ1
22 = 100%
26,40 = x%
26,4*100/22=120%
x=120%
120%-100%=20%
The answer is 20%
Answer:
<h2>The right answer is 415.4 cubic feet.</h2>
Step-by-step explanation:
As you can observe in the image attached, the composite figure is formed by a square prism and a pyramid on top.
We need to find the volum of each part separately.
<h3> Square prism.</h3>

<h3>Square pyramid.</h3>
First, we need to find the height of the pyramid. We already know the height of each triangular face of the pyramid, which divides equally the side.
Let's use Pythagorean's Theorem to find the height of the pyramid.

The height is 4.3 feet, approximately.
Now, we find the volume of the pyramid

The sum of both figures represents the total volume of the composite figure

Therefore, the right answer is 415.4 cubic feet.