The following table presents the time taken to review articles that were submitted for publication to a particular journal during a recent year. A few articles took longer than 6 months to review; these are omitted from the table. Consider the data to be a population. (image) (a) Approximate the variance of the times. Round the answer to at least two decimal places. The variance is (b) Approximate the standard deviation of the times. Round the answer to at least two decimal places. The standard deviation is

Answer:

[tex]-57-39i[/tex]

Step-by-step explanation:

So we have the expression:

[tex](7+2i)(-9-3i)[/tex]

FOIL:

[tex]=7(-9)+7(-3i)+2i(-9)+2i(-3i)[/tex]

Simplify:

[tex]=-63-21i-18i-6i^2[/tex]

Recall that i² is just -1. Thus:

[tex]=-63-21i-18i-6(-1)[/tex]

Simplify:

[tex]=-63-21i-18i+6[/tex]

Combine like terms:

[tex]=(-63+6)+(-21i-18i)[/tex]

Add:

[tex]=-57-39i[/tex]

And we're done!

Answer:

x=8   x=5

Step-by-step explanation:

X^2 - 13x + 40 = 0

What two numbers multiply to 40 and add to -13

-8*-5 = 20

-8-5 = -13

( x-8) (x-5) =0

Using the zero product property

x-8=0    x-5 =0

x=8   x=5

To solve this polynomial equation, we will first factor the left side.

On the left, we have a special type of trinomial

that can be factored as the product of two binomials.

X² breaks down as x · x and we are looking for

the factors of 40 that add to the middle term, -13.

Since the middle term is negative, we use negative factors of 40.

The factors that work are -8 and -5.

So we have (x - 8)(x - 5) = 0.

If (x - 8)(x - 5) = 0, that means that either x - 8 = 0 or x - 5 = 0.

Solving for x in each equation, we have x = 8 or x = 5.

We can write this as the set of numbers {8, 5}.

Step-by-step explanation:

6 2/7is rational

-19is rational but next I dont know

Answer:

10000

Step-by-step explanation:

First, highlight parts of the question. Since it says round to the nearest ten, draw a number line to start. Start by drawing a number line from 9990 to 10000. Whenever a number has the digit from 5 till any number less than 10, you round up. If the number you are trying to round to any digit is less than 5, then you can round down. Since the part of the number that is important for the question is 5.2, we round above. You get 10000 from this.

Answer: 6/7

Step-by-step explanation:

Answer:

.75

Step-by-step explanation:

there is only 1 number

0.75

The decimal forms of rational numbers either end or repeat a pattern. To convert fractions to decimals you just divide the top by the bottom — divide the numerator by the denominator — and if the division doesn't come out evenly, you can stop after a certain number of decimal places and round off.

Answer:

20,27

Step-by-step explanation:

let 13,a,b,34 be consecutive numbers.

a=13

l=34

n=4

l=a+(n-1)d

34=13+(4-1)d

34-13=3d

21=3d

d=21/3=7

a=13+7=20

b=20+7=27

Answer:

  20, 27

Step-by-step explanation:

The difference 34-13 = 21 must be divided into three equal parts. Each is 21/3 = 7.

The numbers are 13+7 = 20, 20+7 = 27. As a check, 27 +7 = 34

The missing numbers are 20 and 27.

Answer:

32 cm²

Step-by-step explanation:

SA = 2(lw + lh + hw)

      = 2(2x2 + 2x3 + 3x2)

      = 2(4 + 6 + 6)

      = 2(16)

      = 32 cm²

Answer:

The answer is (1,-1)

Step-by-step explanation:

The best approach for this problem is to plug in the coordinates into the given inequality.

[tex]7x-3y\geq 10\\[/tex]

(3,4) ------> [tex]7(3)-3(4)=9[/tex]

9 is less than 10 so, we can rule this one out.

(1,0) -------> [tex]7(1)-3(0)=7[/tex]

7 is less than 10 so, we can rule this one out.

(1,2) -------> [tex]7(1)-3(2)=1[/tex]

1 is less than 10 so, we can rule this one out.

(1,-1) -------> [tex]7(1)-3(-1)=10[/tex]

10 is equal to 10, so this is the answer.

Hope this helps!

As mentioned by Mark there are an unlimited number of pairs that satisfy your equation. So let us see how you can characterize these solutions

if 7x - 3y > 10 then

7x > 10 +3y

Now we can substitute any value for y and get the appropriate value for x. For example I can choose y to be 6

then by substitution

7  must be > 10+ 3*6

or 7x must be > 28

or x must be > 4

So all pairs such that x is > 4 and y = 6 are solutions.

I can create an infinite number of pairs choosing any number for y. Likewise I could have chosen x and solved the problem for y. In the above example I chose 6 for y to make the division easy. I could have chosen any number(real or integer) for y and solved the equation for x  to derive appropriate  pairs

Answer:

Step-by-step explanation:

perp. -2/3 slope

y - 4 = -2/3(x + 3)

y - 4 = -2/3x - 2

y = -2/3x + 2

Answer:

-0.5

Step-by-step explanation:

30x - 6x = -6(2)

24x           -12

24              24

x         =      -.5

the answer is C). y= 1/4x + 2

Answer:

$400.27

Step-by-step explanation:

owes $424.04

returns an item for $49.95

-424.04 + 49.95 = -374.09

he now owes $374.09

returns an item for $50.42

-374.09 + 50.42 = -323.67

he now owes $323.67

makes a purchase of $39.19

-323.67 - 39.19 = -362.86

he now owes $362.86

makes a purchase of $37.41

-362.86 - 37.41 = -400.27

he now owes $400.27

Answer:

50%

Ste50p-by-step explan%ation:

Answer:

25.12 inches

Step-by-step explanation:

To find the circumference or the perimeter of a circle it is the diameter times pi. (pi = 3.14) Or you can do radius times 2 times pi.

Answer is 4 times 2 times 3.14 which is 25.12

Answer/Step-by-step explanation:

A. [tex] -7x^2y^2(8x^2y - 5xy + 11xy^2 - 31) [/tex]

[tex] -7x^2y^2(8x^2y) - (-7x^2y^2)(5xy) + (-7x^2y^2)(11xy^2) - (-7x^2y^2)(31) [/tex] (distributive property)

[tex] -56x^4y^3 + 35x^3y^3 - 77x^3y^4 + 217x^2y^2 [/tex] (note: - × - = + and - × + = -)

B. [tex] (\frac{4}{5}t^3 - 5t)(\frac{1}{4}t^2 - 3t) [/tex]

[tex] (\frac{4}{5}t^3)(\frac{1}{4}t^2 - 3t) - 5t(\frac{1}{4}t^2 - 3t) [/tex] (distributive property)

[tex] \frac{4*1}{5*4}t^3*t^2 - \frac{4*3}{5}t^3*t - \frac{5*1}{4}t*t^2 + 15t^2 [/tex]

[tex] \frac{1}{5}t^5 - \frac{12}{5}t^3 - \frac{5}{4}t^3 + 15t^2 [/tex]

Combine like terms

[tex] \frac{1}{5}t^5 - \frac{73}{20}t^3 + 15t^2 [/tex] (note: -12/5 - 5/4 = -73/20)

C. (4x² - 7x + 5)(2x - 5)

4x²(2x - 5) - 7x(2x - 5) + 5(2x - 5) (distributive property)

8x³ - 20x² - 14x² + 35x + 10x - 25

Combine like terms

8x³ - 34x² + 45x - 25

D. (3m² - 5m + 2)²

= (3m² - 5m + 2)(3m² - 5m + 2)

= 3m²(3m² - 5m + 2) - 5m(3m² - 5m + 2) + 2(3m² - 5m + 2) (distributive property)

= 9m⁴ - 15m³ + 6m² - 15m³ + 25m² - 10m + 6m² - 10m + 4

Combine like terms

= 9m⁴ - 15m³ - 15m³ + 6m² + 25m² + 6m² - 10m - 10m + 4

= 9m⁴ - 30m³ + 37m² - 20m + 4

===============================================

Explanation:

2/3 is the probability of passing a test, so 1/3 is the probability of failing

Note how 2/3 and 1/3 add to 3/3 = 1 to represent 100%

The probability of failing 3 tests in a row is (1/3)^3 = (1/3)*(1/3)*(1/3) = 1/27 assuming each test event is independent from one another.

-------

Side note: the probability of passing at least one test is 1-1/27 = 26/27 and the probability of passing all three tests in a row is (2/3)^3 = 8/27

Answer:

0.3

Step-by-step explanation:

1 foot = 12 inches so 3.60/12=0.3

Answer: The amount he earns from lifeguarding = $252 ($18×14). The total amount he needs to make a week is $270.

$270-$252=$18, he needs to earn $18 more from clearing tables.

$18÷9=2, so the minimum number of whole hours clearing tables is 2

Step-by-step explanation:

16=-2x-1

17=-2x

x=-17/2

x=-8.5

(this one isn't in the correct order but it's one of the answers ¯\_(ツ)_/¯

16 = -2x - 1

-8=x-1

-7=x

x=-7

Answer:

x = 45°

Step-by-step explanation:

x + 3x = 180°

--> 4x = 180°

--> x = 180 / 4 = 45°

Step-by-step explanation:

x+3x=180 (sum of linear pair=180)

or, 4x =180

or, x = 180/4

therefore x =45

Answer:

3. 2x+18=4x+26

Step-by-step explanation:

2(x+9)=4(x+7)+2

2x+18=4x+28+2

2x+18=4x+30

The step that made an error in solving this linear equation is step 3.

Hope this helps ;) ❤❤❤

Answer:

Step-by-step explanation:

Find the required diagram to the question in the attachment.

From the diagram it can be seen that the distance of the lines projecting from the centre of the circle to the line segment is equal i,e they are both 8. This means that the length of both chords given will be equal. For the known chord length, it can be seen that the line perpendicular to the chord cuts them at the centre. and since both sides of the chord are parallel, the other sides too will be 10 making the total length to be 10+10 = 20.

Since the length of the known chord is equal to the length of the unknown chord x, hence, the value of x will also be 20

Answer:

D. x=20

Step-by-step explanation:

correct on EDGE2021

Answer: $500

Step-by-step explanation:

The vertical axis of the graph represents the value of the copy machine and the horizontal axis represents the years.

Using the line, one can see that in the first year, the value of the machine went from $7,000 to $6,500.

The loss in value is therefore;

= 7,000 - 6,500

= $500

The needed graph is attached.

Answer:

Straight angle

<----------------------------->

You can determine if an angle is a straight angle only if it is 180 degrees. You can also draw it by drawing a straight line and drawing an arrow facing outward at each end.

Answer:

[tex]\huge\boxed{\sf \frac{x}{3} = 12}[/tex]

Step-by-step explanation:

Let the number be x

4x = 156

Dividing both sides by 4

x = 36

Dividing both sides by 3

[tex]\frac{x}{3}= \frac{36}{3}[/tex]

[tex]\frac{x}{3} = 12[/tex]