Multiply (2-5i)(2+5i)

Answer:

Yes, many times actually. I've aced tests because of brainly

Step-by-step explanation:

Answer:

54= 15 + J

Step-by-step explanation:

j= 39

Answer:

x-30

Step-by-step explanation:

Answer: 5(x-2)=40     5x-10 = 40      5x=50    x=10  

Step-by-step explanation:

^

Answer:

0.04845

Step-by-step explanation:

Probability that less than 7 but more than 4 bulbs from the sample are defective :

P(4 < X < 7) = P(x = 5) + P(x = 6)

Using the binomial probability formula :

P(x =x) = nCx * p^x * (1 - p)^(n - x)

From the question :

p = 0.2 ; 1 - p = 0.8 ; n = 11

P(x =5) = 11C5 * 0.2^5 * 0.8^6 = 0.03876

P(x = 6) = 11C6 * 0.2^6 * 0.8^5 = 0.00969

P(4 < X < 7) = P(x = 5) + P(x = 6)

P(4 < X < 7) = 0.03876 + 0.00969

P(4 < X < 7) = 0.04845

Answer:

Semiconductors are somewhere in-between conductors and insulators. This means that they are specific when it comes to conducting electricity meaning that their conduction of electricity varies based on their condition at the time.

For instance, they can conduct electricity when heated.

Properties:

    1. Perfect insulator at Absolute Zero.

As mentioned above, semi conductors are better at conducting electricity when they are heated. At Absolute zero - the lowest temperature possible -  therefore, these materials would conduct absolutely no electricity thereby making them perfect insulators.

   2. More resistance than Conductors but less than Insulators

As mentioned above, they have properties in-between those of insulators and conductors. One of those is their resistance. They can resist more than conductors but less than insulators.

Answer:

Zane needs 240 strings for 5 harps.

Step-by-step explanation:

All you have to do is multiply

48 * 5 = 240

So, the answer is 240

Hope this helps! :)

Answer:I think 3 years

Step-by-step explanation:

sorry if im wrong

Answer:

I dont know I am sorry I really had to ask a question and i don't have enough points so sorry you can report me if you want but I really need some

Answer:

(2/3)r=30

r=45cm

Step-by-step explanation:

When trying to find a fraction of something, multiply to get your answer:

(2/3) of r = (2/3)r

The blue ribbon can be represented by both 30cm and (2/3)r cm:

(2/3)r=30

2r=90

r=45cm

9514 1404 393

Answer:

Step-by-step explanation:

These are all Law of Cosine problems. A generic expression for the length of side 'c' opposite angle C, which is defined by sides 'a' and 'b' is ...

  c² = a² +b² -2ab·cos(C)

The square root of this gives the side length:

  c = √(a² +b² -2ab·cos(C))

Rearranging the equation, we can obtain an expression for the angle C.

  C = arccos((a² +b² -c²)/(2ab))

These two formulas are used to solve the offered problems.

__

1) AC = √(13² +14² -2·13·14·cos(109°)) ≈ √483.506

  AC ≈ 22.0

__

2) BC = √(7² +10² -2·7·10·cos(123°)) ≈ √225.249

  BC ≈ 15.0

__

3) ∠B = arccos((24² +28² -14²)/(2·24·28)) = arccos(1164/1344)

  ∠B ≈ 30.0°

__

4) ∠B = arccos((6² +9² -14²)/(2·6·9)) = arccos(-79/108)

  ∠B ≈ 137.0°

Answer:

B. 5(2x+5)

Step-by-step explanation:

Factor 5 out of 10x+25. and you get 5(2x+5)

Answer:

B. 5(2x + 5

Step-by-step explanation:

If you have any questions feel free to ask in the comments

Answer: Area of the shape is 168 ft.

Step-by-step explanation: Split the shape into 2 shapes: A rectangle and a triangle.

Area of the rectangle shape is 144 and the area of the triangle is 24. Add them and you get 168.

Answer:

y = x/3 - 5

Step-by-step explanation:

Answer:

y = (1/3)x  - 5 .

Step-by-step explanation:

(-6 , -7) ; (3 ,-4)

Slope = [tex]\frac{y_{2}-y_{1}}{x_{2}-x_{1}}\\[/tex]

          [tex]=\frac{-4-[-7]}{3-[-6]}\\\\= \frac{-4 + 7}{3+6}\\\\= \frac{3}{9}\\\\=\frac{1}{3}[/tex]

m = 1/3   ; (3,-4)

y - y1 = m(x - x1)

[tex]y - [-4]=\frac{1}{3}(x-3)\\\\y + 4 = \frac{1}{3}x-3*\frac{1}{3}\\\\y + 4 = \frac{1}{3}x-1\\\\y =\frac{1}{3}x-1-4\\\\y = \frac{1}{3}x - 5[/tex]

Answer:

Darlene's dog weighs 10 pounds.

Step-by-step explanation: 5 x 10 = 50 and 50 + 10 = 60 pounds.

Hope this helps.

Answer:

If the goal is to break the vases: 3/20 = 15.0% or 0.15

If the goal is to not break the vases: 17/20 = 85.0% or 0.85

Answer:

5

Step-by-step explanation:

Answer:

My best guess is D she can make 4 dozen cokies

Step-by-step explanation:

Answer:

B

Step-by-step explanation:

it is B because  for number A 1+1 =2 2>1.75.  B= 1.5<175, c= 0.5 <1, d. 2>1.75

Answer:

They are all correct.

Step-by-step explanation:

1.

1/2(b)(h)

1/2(4)(6)

1/2(24)

12

2. l x w

7 x 5

35

3. (b)(h)

(8)(4)

32

Answer:

No, there is not sufficient evidence to support the claim that the bags are underfilled

Step-by-step explanation:

A manufacturer of potato chips would like to know whether its bag filling machine works correctly at the 434 gram setting.

This means that the null hypothesis is:

[tex]H_{0}: \mu = 434[/tex]

It is believed that the machine is underfilling the bags.

This means that the alternate hypothesis is:

[tex]H_{a}: \mu < 434[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

434 is tested at the null hypothesis:

This means that [tex]\mu = 434[/tex]

A 9 bag sample had a mean of 431 grams with a variance of 144.

This means that [tex]X = 431, n = 9, \sigma = \sqrt{144} = 12[/tex]

Value of the test-statistic:

[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]

[tex]z = \frac{431 - 434}{\frac{12}{\sqrt{9}}}[/tex]

[tex]z = -0.75[/tex]

P-value of the test:

The pvalue of the test is the pvalue of z = -0.75, which is 0.2266

0.2266 > 0.01, which means that there is not sufficient evidence to support the claim that the bags are underfilled.

Answer:

2/5

Step-by-step explanation:

dsadsadasddsadsadasddsadsadasddsadsadasddsadsadasd

Step-by-step explanation:

8/20=4/10=2/5

done by cancelling

hope it helps

Step-by-step explanation:

Given - In selecting a sulfur concrete for roadway construction in regions that experience heavy frost, it is important that the chosen concrete has a low value of thermal conductivity in order to minimize subsequent damage due to changing temperatures. Suppose two types of concrete, a graded aggregate and a no-fines aggregate, are being considered for a certain road. The table below summarizes data on thermal conductivity from an experiment carried out to compare the two types of concrete.

Type            ni                xi                  si

Graded       42           0.486            0.187

No-fines      42           0.359           0.158

To find - a. Formulate the above in terms of a hypothesis testing problem.

b. Give the test statistic and its reference distribution (under the null hypothesis).

c. Report the p-value of the test statistic and use it to assess the evidence that this sample provides on the scientific question of difference in mean conductivity of the two materials at the 5% level of significance.

Proof -

a.)

Hypothesis testing problem :

H0 : There is significant difference between mean conductivity for the graded concrete and mean conductivity for the no fines concrete.

H1 : There is no significant difference between mean conductivity for the graded concrete and mean conductivity for the no fines concrete.

b)

Test statistic :

[tex]Z = \frac{x_{1} - x_{2} }{\sqrt{\frac{s_{1} ^{2} }{n_{1}} + \frac{s_{2}^{2} }{n_{2}} } }[/tex]

[tex]Z = \frac{0.486 - 0.359 }{\sqrt{\frac{0.03496 }{42} + \frac{0.02496 }{42} } }[/tex]

[tex]Z = \frac{0.127 }{\sqrt{0.001468}}[/tex]

[tex]Z = \frac{0.127 }{0.0377}[/tex]

⇒Z(cal) = 3.3687

Z(tab) = 1.96

As Z (cal) > Z(tab)

So, we reject H0 at 5% Level of significance

p-value = 0.99962

Hence

There is significant difference in mean conductivity at the two materials.

Answer:

I would say about B. 31 cm

Step-by-step explanation:

if you cut the shape into a triangle and a parallelogram, then you can easily guess that the other side of the square is about 4, and 4 x 4 is 16.. then you will multiply 8 by 4 and get 32 and then divide that by 2 and get 16 again, when you add both 16's together, you get 32, but 31 is closest

Answer:

The number of required shelves is 5

You have to find the HCF of 45, 105, and 75.

Answer:

c

Step-by-step explanation:

It's B because 2 equals 86 dgrees since its vertical angles

Answer:

7x+14=0, 7x=-14, x= -2

Step-by-step explanation:

add like terms, then get x on one side, number on the other, then divide both sides by 7

Answer:

90

Step-by-step explanation:

Answer:

It can't be simplified or added together because one is multiplied by x and the other is not

Step-by-step explanation:

Answer: 4x^2

Step-by-step explanation: Multiply that by -1 to get -4x^2 and multiply by 7x to get 28x^3

Answer : 169

Step-by-step explanation:

4(x+19) = 752

4x +76 = 752

4x = 752 - 76

x = 676/4

x=169

Hope this helps ;)

Please mark me the BRAINLIEST