1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
UkoKoshka [18]
3 years ago
7

PLEASE HELP ME NOW!!

Mathematics
2 answers:
Alex Ar [27]3 years ago
8 0
<h2>Hello!</h2>

The answer is:

The correct answer is the first option.

(x-4)^{2}=4+-2\sqrt{7}

<h2>Why?</h2>

To solve the problem, we must remember the following square root property:

\sqrt{ab}=\sqrt{a}\sqrt{b}

So,

We are given the expression:

(x-4)^{2}=28

Now, isolating we have:

First, applying square root to both sides of the equation in order to simplify the quadratic term, we have:

\sqrt{(x-4)^{2} }=\sqrt{28}\\(x-4)=\sqrt{4*7}\\\\x=4+-(\sqrt{4}*\sqrt{7})\\\\x=4+-2\sqrt{7}

Hence, the correct answer is the first option.

(x-4)^{2}=4+-2\sqrt{7}

Have a nice day!

puteri [66]3 years ago
4 0

Answer:

x=4+-2\sqrt{7}

Step-by-step explanation:

To solve, we need to take square root of both sides first:

(x-4)^2=28\\\sqrt{(x-4)^2} =+-\sqrt{28} \\x-4=+-\sqrt{28}

Now we use the property of radical shown below to simplify square root of 28:

Property:  \sqrt{x*y}=\sqrt{x} \sqrt{y}

Now, we have:

x-4=+-\sqrt{28}\\x-4=+-\sqrt{4*7}\\x-4=+-\sqrt{4}\sqrt{7}\\x-4=+-2\sqrt{7}

Now we take 4 to the other side and isolate x:

x-4=+-2\sqrt{7} \\x=4+-2\sqrt{7}

first answer choice is right.

You might be interested in
A library building is in the shape of a rectangle. Its floor has a length of (3x + 5) meters and a width of (5x − 1) meters. The
AleksAgata [21]
The problem says that the expression (3x + 5)(5x − 1) <span>represents the area of the floor of the building in square meters. Therefore,  to solve this problem you have to follow the proccedure shown below.

 1. First, to simplify the expression (3x + 5)(5x − 1) you must apply the distributive property. Then, you obtain:

 15x</span>²-3x+25x-5

 2. Then, you have:

 15x²+22x-5

 3. As you can see, the correct answer is the last option:  15x²+22x-5
7 0
2 years ago
PLEASE HELP NOW NOW NOW PLEASE PLEASE HELP
bija089 [108]

Answer:

$46.00

Step-by-step explanation:

$46.00 - $20 + $5 = $21

7 0
2 years ago
The game of European roulette slots: 18 red, 18 black, and I green. A ball is spun onto the wheel and will eventually land ina s
Anestetic [448]

Answer:

(a) E(x) = -0.081  S.D = 3

(b) E(x) = -0.081  S.D = 1.73

(c) it is less risky to bet $1 in three different rounds as compared to betting $3 in a single round.    

Step-by-step explanation:

(a) You bet $3 on a single round which means that if you win the game, your amount will double ($6), your profit will be $3. Whereas, if you lose the round, your profit will be -$3. You can only bet on red or black and both have 18 slots each.

So, the probability of landing the ball in a red/black slot = 18/37. This is the probability of winning. The probability of losing can be calculated as 1-18/37 = 19/37.

We can make a probability distribution table:

x                    3             -3

P(X=x)         18/37      19/37

Expected value E(x) can be calculated as:

E(x) = ∑ x.P(x)

      = (3)(18/37) + (-3)(19/37)

E(x) = -0.081

Standard deviation can be calculated by the following formula:

Var(x) = E(x²) - E(x)²

S.D = √Var(x)

We need to first calculate E(x²).

E(x²) = ∑x².P(x)

       = (3)²(18/37) + (-3)²(19/37)

       = (9)(18/37) + (9)(19/37)

E(x²) = 9

Var(x) = E(x²) - E(x)²

         = 9 - (-0.081)²

Var(x) = 8.993

S.D = √8.993

S.D = 2.99 ≅ 3

(b) Now, the betting price is $1 and 3 rounds are played. We will compute the expectation for one round and then add it thrice to find the expectation for three rounds. Similarly, for the standard deviations, we will add the individual variances and then consider the square root of it.

E(x) = ∑ x.P(x)

      = (1)(18/37) + (-1)(19/37)

E(x) = -0.027

Standard deviation can be calculated by the following formula:

Var(x) = E(x²) - E(x)²

S.D = √Var(x)

We need to first calculate E(x²).

E(x²) = ∑x².P(x)

       = (1)²(18/37) + (-1)²(19/37)

       = (1)(18/37) + (1)(19/37)

E(x²) = 1

Var(x) = E(x²) - E(x)²

         = 1 - (-0.027)²

Var(x) = 0.9992

The expectation for one round is -0.027

For three rounds,

E(x₁ + x₂ + x₃) = E(x₁) + E(x₂) + E(x₃)

                     = (-0.027) + (-0.027) + (-0.027)

E(x₁ + x₂ + x₃) = -0.081

Similarly, the variance for one round is 0.9992.

Var (x₁ + x₂ + x₃) = Var(x₁) + Var(x₂) + Var(x₃)

                           = 0.9992 + 0.9992 + 0.9992

Var (x₁ + x₂ + x₃) = 2.9976

S.D = √2.9976

S.D = 1.73              

(c) The expected values for both part (a) and (b) are the same but the standard deviation is lower in part (c) as compared to (b). Since the standard deviation is less in part (c), it means that it is <u>less risky to bet $1 in three different rounds as compared to betting $3 in a single round.</u>            

5 0
2 years ago
How do you solve 8x-2y=24
maria [59]
You need to leave the y by himself
8x-2y=24 (subtract 8 on both sides)
-2y=-8x+24 (divide both sides by -2)
y=4x+12 done!
4 0
2 years ago
The charge for the trip is $25 for a car and $50 for a truck.
inessss [21]
Charge for x cars is 25x
Charge for y trucks is 50y
Total charge is 25x + 50y
25x + 50y = 3000
x + 2y = I20
Answer: x + 2y = 120
3 0
2 years ago
Other questions:
  • A pizza shop delivers only one kind of pizza, which is sold for $ 10 $10dollar sign, 10, and costs the pizza shop $ 6 $6dollar s
    12·1 answer
  • Whats the most accurate estimation of 65 77
    8·1 answer
  • If one pound of water has a mass of 453.6 grams, what would be the mass of 2.2 pounds of water?
    6·1 answer
  • Find the area of the shaded region of the figure below. Each small square is 1 cm x 1cm.
    9·2 answers
  • A. 3 times<br> B. 0.3 times<br> C. 1.3 times<br> D. 3 more than
    10·1 answer
  • Express 38% as a fraction in simplest form.​
    9·2 answers
  • What does it mean for the findings of a statistical analysis of data to be statistically​ significant?Choose the correct answer
    12·1 answer
  • 39:24
    14·1 answer
  • The two lines below intersect as shown What is the value of x?
    6·1 answer
  • Can Someone Help me please? Thank you! :D
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!