John believes that the amount of sleep he gets the night before a test and his score on that test are inversely related. On his first exam, he got eight hours of sleep and scored 70 on the exam. To the nearest tenth, how many hours does John believe he must sleep the night before his second exam so that the average of his two exam scores is an 80?

Considering the definition of equation, the equation that represents the statement "Two times a number x increased by 8 is 20" is: 2x + 8= 20

An equation is the equality existing between two algebraic expressions connected through the equals sign in which one or more unknown values, called unknowns, appear in addition to certain known data.

The unknown values represents the number (or numbers), if any, that make the equality true. This unknown number is the solution of the equation.

Considering that:

the equation that represents the statement "Two times a number x increased by 8 is 20" is:

2x + 8= 20

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The equation for the statement "two times a number x increased by 8 is 20" is 2x+8=20.

The given statement is two times a number x increased by 8 is 20.

We need to write the equation to represent this statement.

What is an equation?

In mathematics, an equation is a formula that expresses the equality of two expressions, by connecting them with the equals sign =.

Now, two times a number x=2x

Increased by 8 is 20=2x+8=20

Hence, the equation for the statement "two times a number x increased by 8 is 20" is 2x+8=20.

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The sum of 0.89 and 1.11 will be 2. Then the correct option is D.

The analysis of mathematical representations is algebra, and the handling of those symbols is logic.

Two 10 by 10 grids are shown.

In the first grid, 8 columns and 9 squares are shaded brown and 1 column and 1 square is shaded blue.

The second grid is entirely shaded blue

Then the sum of 0.89 and 1.11 will be

⇒ 0.89 + 1.11

⇒ 2.00

Then the correct option is D.

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The correct option is option B :    -4 ≤ x ≤ 1

Increasing and decreasing functions are functions whose graphs go upwards and downwards respectively as we move towards the right-hand side of the x-axis. Increasing and decreasing functions are also called non-decreasing and non-increasing functions.

Here, from graph

as we can observe from x = -4 graph starts increases upto x = 1 and after that graph becomes constant.

Thus, between x belongs -4 to 1 the graph is increasing.

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Answer:

Ans = A: 57

Step-by-step explanation:

Because

sum of the angke of opposite side of quardilateral triangle is 180°

x°+30°+93°=180°

x°+123°=180°

x°=180°-123°

x°=57°

Hence proved.

The value of x is option A. 57.

A cyclic quadrilateral is a polygon with four sides where all of it's four vertices lie on a circle.

The circle thus formed is called circumcircle or circumscribed circle.

We have a property for the cyclic quadrilateral that the opposite angles formed on the quadrilateral is supplementary.

That is, sum of the opposite angles is 180°.

Here B and D are opposite angles.

So,

∠B + ∠D = 180

9x + x + 30 = 180

Solving,

x = 57

Hence the value of x is 57.

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Given the steps used to calculate the interquartile range, Bryan did not make any mistake.

The interquartile range is the difference between the third quartile and the first quartile.

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Answer:

5, 10, 15

Step-by-step explanation:

the increase in the sequence is 5 so since it starts from 0 which you can find out because 25 is the 5th sequence and that means that +2*5 =25 . x=0

0+ 5 = sequence 1

0+ 5+5 = seq 2

0+5+5+5= seq 3

Answer:

8x+120 is the answer

Step-by-step explanation:

8(x+15)

=8x + 8×15

=8x+120

Answer:

See below ~

Step-by-step explanation:

We need to prove that the figures are similar by applying the various kinds of transformations.

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

Question A :

⇒ Compare the side lengths of A and B

⇒ 2 : 5 (for all sides)

⇒ 1 : 2.5

⇒ Hence, Shape A has been dilated with a scale factor of 2.5 to form Shape B

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

Question B :

⇒ Compare the side lengths of A and B

⇒ A : B = 2 : 6

⇒ A : B = 1 : 3

⇒ Shape A has been dilated with a scale factor of 1/3 to form Shape B

Using the permutation formula, it is found that these offices can be filled in 336 ways.

There are different roles, hence the order in which the people are chosen is important, hence the permutation formula is used.

The number of possible permutations of x elements from a set of n elements is given by:

[tex]P_{(n,x)} = \frac{n!}{(n-x)!}[/tex]

3 people will be chosen from a set of 8, hence the number of ways is given by:

[tex]P_{8,3} = \frac{8!}{5!} = 336[/tex]

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The number of each type Mika bought =x = 6.8 rolls; y= 2.2 rolls.

The number of rolls of film Mika  bought =  9 rolls

The number of rolls that had 36 exposures = x

The number of rolls that had 12 exposures = y

The total number of exposures = 36 + 12 = 48

To find the exposure by one roll = 48/9 = 5.3

If one roll = 5.3 exposure

    x roll    = 36 exposure

Make x roll the subject of formula,

x roll = 36/5.3 = 6.8 rolls

    y roll    = 12 exposure

Make y roll the subject of formula,

y = 12/5.3 = 2.2 rolls

Therefore, the number of each type Mika bought = x = 6.8 rolls; y= 2.2 rolls.

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Answer:

1200 bats

Step-by-step explanation:

78 - 39 = 39

600 x 2 = 1200(bats).

Answer:

40 Rs per kg.

Step-by-step explanation:

solution

Let the rate of tea be x Rs per kg and that of sugar be y Rs per kg.

When Kantabai bought the items by going to the shop,

3/2x+5y+50=700

⇒3x+10y=1300....(I)

When Kantabai bought the items online then

2x+7y=880......(II)

Multiplying (I) with 2 and (II) with 3 we get

6x+20y=2600......(III)

6x+21y=2640.......(IV)

eq.(IV)−(III)

y=40

Putting the value of y =40 in (II)

2x+7(40)=880

⇒2x=880−280=600

⇒x=300

Thus, tea is at 300 Rs per kg and sugar is 40 Rs per kg.

Answer:

47°

Step-by-step explanation:

45+88= 133

180-133=47

Step-by-step explanation:

[tex]12y^{2} + 4y \\4y( \frac{12y^{2} }{4y} + \frac{4y}{4y} ) \\ 4y(3y + 1)[/tex]

Step-by-step explanation:

12y²+4y

divide both sides by 4

therefore,

3y²+y

y(3y+1)

Answer:

The altitude to the hypotenuse of a right triangle forms two triangles that are similar to each other and to the original triangle

The Leg Rule (or Leg geometric mean theorem) relates the length of each leg of a right triangle with the segments projected by them on the hypotenuse.

Step-by-step explanation:

The altitude to the hypotenuse of a right triangle is the mean proportional between the segments into which it divides the hypotenuse. Notice the triangle used with this rule. The leg of a right triangle is the mean proportional between the hypotenuse and the projection of the leg on the hypotenuse.

Answer:

34 degrees

Step-by-step explanation:

Just reverse the cos function   ( you will need a calculator)

arc cos (.8290) = 34 degrees

this is sometimes written as   cos^-1 (.8290)   <====it is the same thing

An expression is defined as a set of numbers, variables, and mathematical operations. The statements that are true are 1, 3, and 5.

In mathematics, an expression is defined as a set of numbers, variables, and mathematical operations formed according to rules dependent on the context.

For the given expression 4x + 9 - y(6x + 7), the following things are can be written,

Thus, the statements that are true are:

Hence, the statements that are true are 1, 3, and 5.

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Answer:

Laila assumed that the lines that formed the angles x and 18° added up to 90. This is in fact false because of the lack of the square marking to signify it as a right or 90 degree angle.

The probability that Bridget makes all three free throws to win the game is; 42.2%

We are told that the probability of Bridget making her free throw correctly is 75%.

Now, if she has to get all three free throws correctly, then the probability for that is;

P(3 free throws correct) = 0.75 * 0.75 * 0.75

P(3 free throws correct) = 0.421875 ≈ 42.2%

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Three points must be removed from this graph so that it will be a function

The points are given as:

(-3, 2), (-3, 3), (1, 4), (1, -4), (2, -4), (2, -2).

For a set of point to represent a function;

Each x coordinate must point to only one y coordinate

From the given points, we have the following highlights:

In the above highlights, one point each must be removed.

This means we have a total of 3 points

Hence, three points must be removed from this graph so that it will be a function

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Answer:

C. 3 points

Step-by-step explanation:

The given expression is [tex]\dfrac{ r^2-r-6}{(r-2)(r-3)}[/tex]. the option C [tex]\dfrac{ (r+2)}{(r-2)}[/tex]is correct.

Usually, simplification involves proceeding with the pending operations in the expression.

Simplification usually involves making the expression simple and easy to use later.

The given expression is

[tex]\dfrac{ r^2-r-6}{(r-2)(r-3)}[/tex]

By solving the numerator

[tex]r^2-r-6\\\\r^2 - (3-2)r- 6\\\\(r-3)(r+2)[/tex]

Put the solution in the above equation

[tex]\dfrac{ (r+2)(r-3)}{(r-2)(r-3)}[/tex]

[tex]\dfrac{ (r+2)}{(r-2)}[/tex]

Therefore, the option C is correct.

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The answers to the three shapes are:

Figure 7; perimeter = 16.2mm, area = 12.64 square mm

Figure 8; perimeter = 15.2inches, area = 9.61 square inches

Figure 9; perimeter = 21.47yards,  area = 16.81 square yards

Perimeter is the outside boundary of a plane shape.

Analysis:

for figure 7, perimeter = s + s + s = 3s = 3(5.4) = 16.2mm

                   Height of triangle = [tex]\sqrt{((5.4)^{2} - (2.7)^{2} }[/tex] = 4.68

            Area of triangle = 1/2 base x height = 1/2 x 5.4 x 4.68 = 12.64[tex]mm^{2}[/tex]

For figure 8, perimeter = b + b + a = 5.9 + 5.9 + 3.4 = 15.2 inches

                     Height of triangle = [tex]\sqrt{(5.9)^{2} - (1.7)^{2} }[/tex] = 5.65inches

           Area of triangle = 1/2 base x height = 1/2 x 3.4 x 5.65 = 9.61[tex]inches^{2}[/tex]

For figure 9, perimeter = b + a + c = 8.2 + 4.1 + 9.17 = 21.47yards

           Area of triangle = 1/2 x base x height = 1/2 x 8.2 x 4.1 = 16.81[tex]yards^{2}[/tex]

In conclusion, the perimeter and area of the given shapes are:

Figure 7; perimeter = 16.2mm, area = 12.64 square mm

Figure 8; perimeter = 15.2inches, area = 9.61 square inches

Figure 9; perimeter = 21.47yards,  area = 16.81 square yards

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Answer: A right angle

Step-by-step explanation:

Perpendicular lines form right angles

Answer:

90 degree

Step-by-step explanation:

I assume you know that there are n total n-th roots for any non-zero complex number.

(If you're looking for "the" principal root, you'll have to specify which branch you're calling the principal branch of the n-th root function.)

Start by writing [tex]1 - i\sqrt3[/tex] in exponential form. We have modulus/magnitude

[tex]|1 - i\sqrt3| = \sqrt{1^2 + (-\sqrt3)^2} = \sqrt4 = 2[/tex]

and [tex]1-i\sqrt3[/tex] lies in the fourth quadrant of the complex plane, so its argument is

[tex]\arg(1-i\sqrt3) = \tan^{-1}\left(-\sqrt3\right) = -\dfrac\pi3[/tex]

Then the exponential form is

[tex]1 - i \sqrt3 = 2 \exp\left(-i\dfrac\pi3\right)[/tex]

(where [tex]\exp(x) = e^x[/tex], if you're not familiar with the notation)

By de Moivre's theorem, we have the fourth roots

[tex]\sqrt[4]{1 - i\sqrt3} = \sqrt[4]{2} \exp\left(i \dfrac{-\frac\pi3+2k\pi}4\right)[/tex]

where [tex]k\in\{0,1,2,3\}[/tex], so that we have a choice of

[tex]\sqrt[4]{1 - i\sqrt3} = \begin{cases} \sqrt[4]{2} \exp\left(-i\dfrac\pi{12}\right) \\\\ \sqrt[4]{2} \exp\left(i\dfrac{5\pi}{12}\right) \\\\ \sqrt[4]{2} \exp\left(i\dfrac{11\pi}{12}\right) \\\\ \sqrt[4]{2} \exp\left(i\dfrac{17\pi}{12}\right) = \sqrt[4]{2} \exp\left(-i\dfrac{7\pi}{12}\right) \end{cases}[/tex]

(I rewrote the exponent to the last root just to be consistent about having each argument between -π and π radians)

If you want these in rectangular form (a + bi), sorry, that's where I draw the line; it can be done with simple trigonometry and algebra, but it's rather tedious, and the exponential forms are far more compact.

Answer:

-12X^7-27X^6

Step-by-step explanation:

-3x^6(-4X+9)=(-3X^6*)(4X^1)+-27X^6=-12X^7+-27X^6

The operation that should be completed first to find the value of the expression is 6 - 3

The expression is given as:

12 + 30/(6 - 3) + 1

When solving an expression;

All expressions in the bracket must be first evaluated

This means that the operation that should be completed first is 6 - 3

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Answer:

[tex]13\frac{1}{3} \pi[/tex]

Step-by-step explanation:

First, find the area of the small circle whose radius is 3cm.

[tex]A = \pi r^{2} \\A = \pi (3^{2})\\A = \pi (9)\\A = 9\pi \\[/tex]

Next, find the area of the large circle. First, you need to find the radius of the large circle by adding the 3 and 4.

Radius of large circle.

3 + 4 = 7 cm

Area of large circle:

[tex]A = \pi r^{2} \\A = \pi (7^{2})\\A = \pi (49)\\A = 49\pi \\\\[/tex]

Now subtract the area of the small circle from the large circle since the shaded area doesn't include the small circle.

[tex]49\pi -9\pi =40\pi[/tex]

Finally find the shaded area. To do this first find what degree of the circle is shade by dividing 120 by 360.

120/360 = 1/3

Now multiply the area by 1/3, or you can divide it by 3

[tex]\frac{40\pi }{3} =13\frac{1}{3} \pi[/tex]

Answer:

Image included:

Step-by-step explanation: