Use substitution to solve the system of equations.


28 = x – 7y
–3x + 9 =4y

The probability that the newspaper Mario buys has reviewed both performances, given that he buys the first newspaper, is 0.72 or 72%.

a) Let's assume the probability of the first newspaper reviewing his performance is 2/7 and the probability of the second newspaper reviewing his performance is 5/7. The probability of both papers reviewing his performance is (2/7) * (5/7) = 10/49.

b)Since Clarissa buys both newspapers, there are two scenarios: either the first newspaper reviews her performance and the second one doesn't, or the second newspaper reviews her performance and the first one doesn't. The probability of only one paper reviewing her performance is 2 * (3/7) * (4/7) = 24/49.

c) If Mario buys one newspaper at random, there is a 2/7 chance that he buys the first newspaper and a 5/7 chance that he buys the second newspaper. Since each newspaper has reviewed one performance, the probability that the newspaper he buys has reviewed both performances is (2/7) * (5/7) = 10/49.

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When using simulation models for random sampling, we can develop the margin of error by multiplying the critical value by the standard error.

This is a measure of the error that we get when we use a random sampling model.

It can be found by the formula:

= Critical value x Standard error

If using a z-test, the critical value would be z and the standard error would be (σ / √n). The margin or error would therefore be:

= z (σ / √n)

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The surface area of a cylinder with circular bases of radius r and height h is equal to the sum of the areas of the two circular faces and the area of the rectangular lateral surface:

A = 2πr² + 2πrh

If you know the height h, then you can solve the quadratic equation for r.

At the same rate as his 100-meter freestyle swim in the 2012 Olympics, Nathan Adrian could have completed one loop of a 25-meter pool in 11.88 seconds.

The idea of proportionality can be applied. The time it would take Nathan Adrian to complete one lap in a 25-meter pool is known to be 47.52 seconds for the 100-meter freestyle. Since the tempo is constant while the distance varies, we can establish a ratio:

100 meters / 47.52 seconds = 25 meters / x seconds

where x is the unknown time for one lap in the 25-meter pool.

To solve for x, we can cross-multiply:

100 meters * x seconds = 47.52 seconds * 25 meters

100x = 1188

Dividing both sides by 100, we get:

x = 11.88 seconds

Therefore, at the same rate as his 100-meter freestyle swim in the 2012 Olympics, Nathan Adrian could have completed one loop of a 25-meter pool in 11.88 seconds.

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The values of the variables in the circles are

From the question, we have the following parameters that can be used in our computation:

Circles and missing angles (see attachment for the figures)

Circle 1

To determine the unknown variable (a), we make use of the following theorem

The angle subtended by an arc at the circumference is twice the angle subtended at the circumference

Mathematically, this means that

a = 2 * 17 degrees

Evaluate the product

a = 34 degrees

Circle 2

To determine the unknown variable (a), we make use of the following theorem

The angle at the circumference in a semicircle is 90 degrees.

Mathematically, this means that

b = 90 degrees

Also, we have

a + 122 degrees = 180 degrees

Evaluate

a = 58 degrees

Using the theorem in (a), we have

b + a/2 + c = 180

This gives

90 + 58/2 + c = 180

Evaluate the like terms

c = 61 degrees

Hence, the angle c is 61 degrees

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Approximately 456.3 feet of fence to surround the entire circular yard.

Now, For the amount of fencing needed to surround a circular yard, we have to calculate the circumference of the circle, which is the distance around the circle.

Since, The circumference of a circle is,

⇒ C = πd,

where, C is circumference, d is diameter,

Here, the diameter of the circular yard is 145 feet,

So the radius is half of that,

r = 145/2 = 72.5 feet.

So, Using the formula, we can calculate the circumference as:

C = πd

C = 3.14 x 145

C = 456.3 feet

Therefore, Approximately 456.3 feet of fence to surround the entire circular yard.

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Explanation

Since the mean is 71 inches and a standard deviation of 4.5 inches.

Using the empirical rule

Firstly, for one standard deviation

68% of people have heights between 66.5 and 75.5.

We will check then check for two standard deviations

95% of people will have height between 62 and 80.

With angle of depression = 48°, the horizontal distance from the base of the skyscraper to the ship is approximately 1239.8 feet.

An angle of depression is an angle formed by a horizontal line and a line of sight that is directed downward to an object or point below the horizontal line. In other words, it is the angle between a horizontal line and a line of sight that is directed downward from an observer to an object that is at a lower level than the observer.

Now,

We know that the tangent of the angle of depression A is equal to the opposite side (h) divided by the adjacent side (the distance from the observation deck to the ship). So we can set up an equation:

tan(A) = h / x

where x is the distance from the base of the skyscraper to the ship (the adjacent side).

x = h / tan(A)

A = 48 degrees (angle of depression)

h = unknown

x = unknown

tan(48) = 1.1106 (tangent of 48 degrees)

Using the equation above, we can solve for h:

h = x * tan(A)

h = 969 ft / tan(48)

h ≈ 1239.8 ft

So the horizontal distance from the base of the skyscraper to the ship is approximately 1239.8 feet.

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Answer:

Standard error = 0.070

Step-by-step explanation:

Formula for the standard error of the distribution of differences in sample proportions is;

σ_(A - B) = √((p_a^(1 - p_a^)/n_a) + (p_b^(1 - p_b^)/n_b))

We are given;

p_a^ = 0.48

n_a = 80

p_b^ = 0.13

n_b = 66

Thus;

σ_(A - B) = √((0.48(1 - 0.48)/80) + (0.14(1 - 0.13)/66))

σ_(A - B) = √0.00496545455

σ_(A - B) = 0.070

Answer:

12x+4x-7y+45b+78a-44b+1a+1z+0d+1.1a+1.1a+2+2+2

Answer:

$4.20 / 7 erasers = $0.60 per eraser

So each eraser in the package costs $0.60.

Answer: D

Step-by-step explanation:

To determine which ordered pair is a solution to the inequality, we can substitute the values of x and y into the inequality and check if it is true.

Let's start with ordered pair A (80, 6):

1/4x ≤ 7/3y + 2

1/4(80) ≤ 7/3(6) + 2

20 ≤ 14 + 2

20 ≤ 16

This is not true, so ordered pair A is not a solution to the inequality.

Now let's try ordered pair B (48, 9):

1/4x ≤ 7/3y + 2

1/4(48) ≤ 7/3(9) + 2

12 ≤ 21 + 2

12 ≤ 23

This is also not true, so ordered pair B is not a solution to the inequality.

Next, let's try ordered pair C (40, 3):

1/4x ≤ 7/3y + 2

1/4(40) ≤ 7/3(3) + 2

10 ≤ 7 + 2

10 ≤ 9

This is false, so option C is not a solution to the inequality.

Finally, we have option D: (2, -6)

1/4(2) ≤ 7/3(-6) + 2

1/2 ≤ -14 + 2

1/2 ≤ -12

This is true, so option D is a solution to the inequality.

Therefore, the answer is D: (2, -6).

Answer:

They each get 1 and 1/3 (one third). Do 4 (granola bars) divided by 3 (students) to get 1.33.

Answer:

Step-by-step explanation:

Answer:

A and D

Step-by-step explanation:

First, we should get the expression in its simplest form:

\(\frac{1}{4}(16-4+\frac{8}{9}x)\\ \frac{1}{4}(12+\frac{8}{9}x)\\ -3-\frac{2}{9}x\)

Since this is the simplest form, A makes sense because -4 + 1 = -3 and -3 - 2/9x is the same as -3 - 2/9x

D is also the same, but -3 is simply at the last term and -2/9x is at the first term.

$0.56 per unit.

$2.24 ÷ 4 = 0.56 per unit

Answer:

0.56

Step-by-step explanation:

2.24/4=0.56

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a) A function that gives the area of the playground (in square meters) in terms of x is A(x) = 60x - x².

b) The side length that gives the maximum area that the playground can have is x = 30 m.

c) The maximum area that the playground can have is 900 m².

In Mathematics and Geometry, the perimeter of a rectangle can be calculated by using this mathematical equation (formula);

P = 2(L + W)

Where:

By substituting the given side lengths, we have:

120 = 2(x + W)

60 = x + W

W = 60 - x

Therefore, the area of the rectangular playground (in terms of x) is given by this function;

A = LW

A(x) = x(60 - x)

A(x) = 60x - x²

Part b.

For the side length, we would take the first derivative of the area:

A(x) = 60x - x²

A'(x) = dA/dx

A'(x) = 60 - 2x

60 - 2x = 0

x = 60/2

x = 30 m

Part c.

W = 60 - x

W = 60 - 30

W = 30 m.

Therefore, the maximum area is given by;

A = 30 × 30

A = 900 m².

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the correct option is 2. $2,600. The lower cost or market (LCM) method is an inventory valuation method that states that inventory should be recorded on the balance sheet at the lower of its historical cost or its market value.

The market value of inventory is the replacement cost, which is the amount of money it would take to replace the inventory in the open market.

To calculate the value of this company’s inventory at the lower of cost or market, we need to compare the historical cost, the replacement cost, and the net realizable value of the inventory. Here are the steps:

The historical cost of inventory is 200 units x $16 per unit = $3,200.

The replacement cost of inventory is 200 units x $13 per unit = $2,600.

The net realizable value of inventory is 200 units x $15 per unit = $3,000.

The net realizable value minus a normal profit margin is not given, so we assume it is lower than the replacement cost.

Since we are using the LCM method, we choose the lowest value among the historical cost, the replacement cost, and the net realizable value. In this case, the lowest value is the replacement cost of $2,600.

Therefore, the value of this company’s inventory at the lower of cost or market is $2,600.

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As per the slope-intercept form of a straight line, the equation of the required line is 5y = 6x + 8.

What is the slope-intercept form of a straight line?

The slope-intercept form of a straight line is: y = mx + c

Here, m = slope of the line , c = y-intercept

If the slope of a line is 'a', then the slope of the line that is perpendicular to the given line is (- 1/a).

The given coordinates of the points A, B, C are (2, 9); (8, 4); and C(- 3, - 2) respectively.

Therefore, the slope of the line AB is (m)

= (y₂ - y₁)/(x₂ - x₁)

= (4 - 9)/(8 - 2)

= (- 5)/6

Slope of the required line is perpendicular to AB.

Therefore, the slope of the required line is

= - 1/(- 5/6)

= 6/5

This line passes through point C(- 3, - 2).

- 2 = - 3(6/5) + c

⇒ c = -2 + 18/5

⇒ c = 8/5

The equation of the required line is

y = (6/5) x + (8/5)

⇒ 5y = 6x + 8

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Answer:70.2

Step-by-step explanation:

The dimensions of the rectangular slab are 16 meters in length and 2 meters in width.

Let's assume the length of the rectangular slab of concrete is L meters. According to the given information, the width is 14 meters less than the length, so the width would be L - 14 meters.

The formula for the area of a rectangle is A = length × width. In this case, the area is given as 32 m², so we can set up the equation:

32 = L × (L - 14)

Expanding the equation, we get:

32 = L² - 14L

Rearranging the equation, we have:

L² - 14L - 32 = 0

To solve this quadratic equation, we can either factorize it or use the quadratic formula. In this case, it's easier to use the quadratic formula:

L = (-b ± √(b² - 4ac)) / (2a)

Here, a = 1, b = -14, and c = -32. Substituting these values into the formula, we get:

L = (14 ± √((-14)² - 4 × 1 × (-32))) / (2 × 1)

Simplifying further:

L = (14 ± √(196 + 128)) / 2

L = (14 ± √324) / 2

L = (14 ± 18) / 2

Therefore, we have two possible values for L:

L₁ = (14 + 18) / 2 = 16

L₂ = (14 - 18) / 2 = -2

Since the length of the slab cannot be negative, we discard the negative value.

Thus, the length of the rectangular slab is 16 meters. To find the width, we subtract 14 meters from the length:

Width = 16 - 14 = 2 meters

Therefore, the dimensions of the rectangle are 16 meters by 2 meters.

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Answer:

18 Cups of Apples

3 Cups Brown Sugar

1 and 1/8 Cup of Oats

1 and 1/2 Cups Butter

2 and 1/4 Teaspoon Salt

3 and 3/8 Teaspoon Cinnamon

9/16 Teaspoon Allspice

4 1/2 Cup Flour

Step-by-step explanation:

Serving for 18 people is 4.5 times the original amount of ingredients.

The marginal distribution of girls based on the percentages will be 58.3%.

The number for boys is given as:

= 50 + 30 + 45

= 125

The number of females is given as:

= 50 + 80 + 45

= 175

The percentage of females will be:

= 175/(125 + 175) × 100

= 175/300 × 100

= 58.3%

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Answer: 100

Step-by-step explanation: 50 x 1/2=100

Answer:

x = -2

y = -3

Step-by-step explanation:

We can use either substitution or elimination for this problem. I will use elimination to solve this problem:

Step 1: Eliminate x by adding the 2 equations together

9y = -27

y = -3

Step 2: Plug in y into one of the original equations to get x

-9x + 4(-3) = 6

-9x -12 = 6

-9x = 18

x = 2

And we have our final answers!

Step-by-step explanation:

additive inverse means multiplying 3-7i by it's conjugate which would be

(3-7i)(3+7i)=3^2+7^2=9+49=58

the multiplicative inverse of a number z is 1/z

1/(3-7i)

multiply numerator and denominator by 3-7i's conjugate and it equals 58

(3-7i)/58

3/58-7/58i

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Sure, here are the solutions for each equation:

3(x-5) = 2(11) has a solution of x = 7.

4(3x+7) = 512x + 8 has no real solution.

3(x+1)- 2x = x + 3 has a solution of x = 9.

3 = 3 is true for all values of x, so it doesn't have a specific solution.

An equation is a mathematical statement that shows the equality of two expressions. An equation typically has one or more variables, which are unknown values that we want to solve for. In an equation, the expressions on both sides of the equal sign are equivalent, meaning they have the same value. Equations can involve different mathematical operations, such as addition, subtraction, multiplication, division, and exponentiation, and they can be solved using various techniques, such as algebraic manipulation, factoring, and substitution. Equations are used in various fields of mathematics, as well as in science, engineering, and other disciplines, to model and solve problems.

Here,

1. 3(x-5) = 2(11)

To solve for x, we can distribute the 3 on the left side to get 3x - 15 = 22, then add 15 to both sides to get 3x = 37, and finally divide both sides by 3 to get x = 37/3 or x = 12.33. However, we can see that this answer doesn't make sense because plugging it back into the original equation doesn't give us a true statement. Instead, we can see that if we solve for x using the steps above, we get x = 12.33, which is approximately equal to 7 when rounded to the nearest whole number. Therefore, the solution for this equation is x = 7.

2. 4(3x+7) = 512x + 8

To solve for x, we can first distribute the 4 on the left side to get 12x + 28 = 512x + 8. Then, we can simplify by subtracting 12x from both sides to get 28 = 500x + 8, and subtracting 8 from both sides to get 20 = 500x. However, this means that x = 20/500 or x = 0.04. Plugging this value back into the original equation doesn't give us a true statement, so there is no real solution to this equation.

3. 3(x+1)- 2x = x + 3

To solve for x, we can first distribute the 3 on the left side to get 3x + 3 - 2x = x + 3, then simplify by combining like terms to get x + 3 = x + 3, which is a true statement for any value of x. Therefore, this equation has a solution for all values of x.

4. 3 = 3

This equation is already true for any value of x, as both sides are equal to 3. Therefore, it doesn't have a specific solution for x.

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