Solve each system by substitution.
4x + y = 19
6x + 7y=1

Answer:

y = 2.60 (to 3sf)

Step-by-step explanation:

Since x is directly proportional to y², then x = ky², where k is a constant.

When x = 4, y = 3,

 4 = k(3)²

 4 = 9k

9k = 4

∴[tex]k =\frac{4}{9}[/tex]

∴ When x = 3,

[tex]\frac{4}{9}y^{2} = 3[/tex]

∴y = 2.60 (to 3sf)

Greek mathematicians, who were first influenced by the Egyptians, would go on to produce innovations like Pythagoras' theory of right-angled triangles and, by concentrating on the abstract, bring accuracy and clarity to venerable mathematical conundrums.

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Answer:

x = - 7 , x = 10

Step-by-step explanation:

(x - 10)(x + 7) = 0

equate each factor to zero and solve for x

x - 10 = 0 ⇒ x = 10

x + 7 = 0 ⇒ x = - 7

Using the properties of ratio we calculate that the largest land inheritance was sold at $825000 .

The ratio in which the land is divided is 2:3:5

Let the common ratio be x .

Hence the land is divided which has a combined area of 2750 acres.

Now, 2x+3x+5x = 2750

or, 10x = 2750

or, x = 275

Now the person with the highest inheritance will be having land:

= 5× 275

= 1375 acres

Cost of the land at $600 per acre

= 600 × 1375

= $825000

therefore the cost of the land is  $825000

A ratio can therefore be thought of as an ordered pair of integers, a fraction with the first number in the numerator and the second in the denominator, or as the value represented by this fraction.

Ratios of counts that are expressed in terms of (non-zero) natural numbers are rational numbers and occasionally natural numbers as well. The ratio of two numbers is a dimensionless number when they are measured using the same unit, which happens frequently.

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The value of x are, x = 9, x = -9.

What is undefined expression?

A mathematical expression that consists of a number of variables and arithmetic operations but has no known solution is referred to as an undefined expression. Any expression that has the symbol ∞ in any part of its expression or that has zero in the denominator is regarded as being undefined.

When the denominator is zero, a rational expression cannot be defined. Set the denominator equal to zero and solve the ensuing equation to get the values that render a rational expression undefined.

So, to find the x - values set denominator equal to zero.

[tex]x^2 - 81 = 0\\x^2 = 81\\x = \sqrt{81}[/tex]

x = ± 9

Therefore, the value of x are, x = 9, x = -9.

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For each solution, the chemist needs 80 liters of 82% solution and 20 liters of 52% solution.

So, a chemist intends to create a 76% acid solution in 100 liters.

He will create it by combining an acid solution that is 52% with an acid solution that is 82%.

Now, calculate as follows:

0.82x + 0.52(100-x) = 0.76(100) (100)

Hence, for each solution, the chemist needs 80 liters of 82% solution and 20 liters of 52% solution.

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The circumference of the circle to the nearest hundredth is 21.98 inches.

The circumference of a circle is the measure of the boundary or the length of the complete arc of a circle.

The circumference of a circle is the perimeter of the circle. It's the wholes boundary of the circle.

The circumference of the circle can be found as follows:

circumference of a circle = 2πr

where

Therefore,

diameter of the circle = 7 inches

radius of the circle = 7 / 2 = 3.5 inches

Hence,

circumference of a circle = 2 × 3.14 × 3.5

circumference of a circle = 21.98 inches

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The value of k so that the system of equation has no solution is k = -4

Since we have the system of equations

kx + 6y = 6

y = 2/3x - 4

For the system of equations to have no solution, the determinant coefficient matrix must be zero.

Re-arranging the equations, we have

kx + 6y = 6

-2/3x  + y = - 4

So, the coefficient matrix is

[tex]\left[\begin{array}{ccc}k&6\\-2/3&1\end{array}\right][/tex]

So, the determinant D = k × 1 - (-2/3) × 6

= k + 2/3 × 6

= k + 2 × 2

= k + 4

Since the determinant must be zero for the system of equations to have no solution, we have that

D = 0

k + 4 = 0

k = -4

So, the value of k = -4

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Answer:

  16 square inches

Step-by-step explanation:

You want the largest rectangle that can be inscribed in a semicircle with radius 4 inches.

The equation of a circle centered at the origin with radius 4 is ...

  x² +y² = 16

The height (y) of a rectangle whose corner is on the circle will be ...

  y = √(16 -x²)

The width of such a rectangle is 2x, so the area of it is ...

  A = WH = (2x)√(16 -x²)

The maximum area will be had when the derivative of the area with respect to x is zero.

  A' = 2√(16 -x²) - 2x²/√(16 -x²) = 0

Multiplying by √(16 -x²)/2 gives ...

  16 -x² -x² = 0

  16 = 2x²

  x = √(16/2) = 2√2

The corresponding area of the rectangle is ...

  A = 2(2√2)√(16 -(2√2)²) = 16

The largest rectangle has an area of 16 square inches.

__

Additional comment

As is often the case with rectangle optimization problems, the largest rectangle that can be inscribed in the quarter circle in each quadrant is a square. It has a diagonal of 4 inches, so an area of 4²/2 = 8 square inches.

The attachment shows the cubic curve representing the area of that square as a function of its width. As above, the rectangle area is double this value.

Answer:

[tex]\dfrac{4}{35}[/tex]

Step-by-step explanation:

Dividing a number is the same thing as multiplying by its reciprocal. So:

[tex]\dfrac{4}{7} \div 5 = \dfrac{4}{7} \cdot \dfrac{1}{5}[/tex]

Finally, simplify by multiplying out the numerators and the denominators.

[tex]\dfrac{4}{7} \cdot \dfrac{1}{5} = \dfrac{4 \cdot 1}{7 \cdot 5} = \dfrac{4}{35}[/tex]

Answer:

4/7 divided by 5 is 4/35

Step-by-step explanation:

Step 1: Convert 5 into an improper fraction

    A. 5 = 5/1

Step 2: Divide 4/7 by the reciprocal of 5/1

    B. 4/7 ÷ 1/5 = 4/35

A and B are two sets, and the set formula is given as n(AB) = n(A) + n(B) - n(AB), where n(AB) denotes the number of elements present in either A or B, and n(AB) is the number of elements present in both A and B.

Drawing Venn diagrams, as seen below, is the simplest method for solving set issues.

The total number of elements in any set A or B is n(AB).

The total number of elements in sets A and B is n(AB).

n(AB) is equal to n(A) + n(B) - n(AB)

U={a,b,c,d,e,f}

X={a,b,c,d},

Y={c,d,e}

Z={b,d,f}

(XUY) =  (a,b,c,d,e)

(XUZ)​ =(a,b,c,d,f)

(XUY)U(XUZ)  =  (a,b,c,d,e,f)

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I need help too on this one

Answer:

you lowest tempeture in the mesosphere is -96

Step-by-step explanation:

The time taken to reach the maximum height is 1.25 seconds.

The maximum height is 32 feet.

A function is a relationship between inputs where each input is related to exactly one output.

Example:

f(x) = 2x + 1

f(1) = 2 + 1 = 3

f(2) = 2 x 2 + 1 = 4 + 1 = 5

The outputs of the functions are 3 and 5

The inputs of the function are 1 and 2.

We have,

h(t) = -16t² + 40t + 7

Differentiating with respect to t.

h'(t) = -16 x 2t + 40

0 = -32t + 40

32t = 40

t = 40/32

t = 1.25

The maximum height.

h(t) = -16t² + 40t + 7

h(1.25):

= -16 x 1.25 x 1.25 + 40 x 1.25 + 7

= -25 + 50 + 7

= 32 feet

Thus,

The time taken to reach the maximum height is 1.25 seconds.

The maximum height is 32 feet.

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Answer:

  0.591

Step-by-step explanation:

You want the probability that a height falls between 50.5 and 53.7 when the distribution of heights is normal with mean 53.4 and standard deviation 1.2. All measurements are in inches.

The area under the normal distribution curve with mean 53.4 and standard deviation 1.2 can be found using a suitable calculator. The one in the attachment shows the area between 50.5 and 53.7 is about 0.591

P(50.5 < X < 53.7) ≈ 0.591

__

Additional comment

Any spreadsheet and most graphing calculators have the necessary probability functions. Many special-purpose apps also can answer this question. A calculator answer is shown in the second attachment.

The percentage of the profit gain by karen on a pack of 8 bottles  is 220%.

Karen buys a pack of bottles of water. = 8

Karen sells all 8 bottles of water for rupees =  50p each

=  50p/100 each

= 0.5 rupees

Total rupees for 8 bottles = 8 x 0.5 = 4

The pack costs  = 1.25

Profit % = (Profit / C.P.) × 100

Profit = SP - CP

=  4 - 1.25

= 2.75

then using these values in equation we get :

profit = [tex]\frac{4 - 1.25}{1.25} * 100[/tex]

profit = (2.75/1.25 )x 100

profit = 2.2 x 100 = 220

profit = 220%

The percentage of the profit gain by karen on a pack of 8 bottles  is 220%.

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According to the discriminant, the quadratic equation y = 2 · x² - x + 1 has two roots that are complex and conjugate.

Quadratic equations are algebraic expressions of the form a · x² + b · x + c, where a, b, c are real coefficients. In this case, we can infer the nature of its roots by means of a discriminant:

D = b² - 4 · a · c

Whose possible results are listed below:

If we know that a = 2, b = - 1 and c = 1, then the nature of the roots of the polynomial:

D = (- 1)² - 4 · 2 · 1

D = 1 - 8

D = - 7

Then, the quadratic equation has two conjugate complex roots.

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Answer:90 t shirts

Step-by-step explanation: 20:30 is the ratio and if they make 60 sweatshirts, they would have to make 90 tshirts as well. this would keep the same ratio

The domain of the exponential function in this problem is given as follows:

0 ≤ n ≤ 5.

The exponential function in this problem is defined by the rule presented as follows:

g(n) = 10(1.02)^n.

In which the variables are listed as follows:

When the study was finished, the height of the flower was of 11.04 inches, hence the day at which the study was finished is obtained as follows:

10(1.02)^n = 11.04

(1.02)^n = 11.04/10

log[(1.02)^n] = log(11.04/10)

Applying the logarithm of power property, we have that:

nlog(1.02) = log(11.04/10)

n = log(11.04/10)/log(1.02)

n = 5.

The domain is the number of days for which the student was realized, hence:

0 ≤ n ≤ 5.

As the number of days cannot assume negative values.

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Answer:

6 months.

Step-by-step explanation:

Answer:

-6a -13b - 12c + 4

Step-by-step explanation:

-12a + -5b - 12c + 6a - 8b - (-4)

-12a + -5b - 12c + 6a - 8b + 4   [a "- -" = +]

(-12a + 6a) -(5b -8b) - 12c + 4    [Group like terms.]

-6a -13b - 12c + 4

Answer:

f(x) = 4x + 10

Step-by-step explanation:

The given information is in the form f(x) = y.

f(0) = 10 means if x is 0, y is 10. This is the point (0,10)

Likewise, f(6) = 34

means when x is 6, y is 34. That is the point (6,34).

Slope is y-y / x-x

34-10 / 6-0

is 24/6.

The slope is 4.

The y-intercept is where x is 0, that is 10.

y=mx+b is slope-intercept form. Fill in the slope, 4 for m and the y-intercept, 10, for b.

y = 4x + 10

but they also asked to call it f, so for function notation, use f(x) instead of y.

f(x) = 4x + 10

the equation representing amount paid by Peggy and Daniel for songs is

the cost per download for members and for non-members

from the question the following information can deduced

Daniel is not a member of the club and downloaded 85 at rate of $0.35

total amount paid by Daniel

= 85 * 0.35

= 29.75

Peggy is a member and downloaded 105 songs at a rate of $x

Total amount paid by Peggy

= 105 * $x

= 105x

equating both amounts

105x = 29.75

cost of downloading a song for members, x0.28

105x = 29.75

x = 29.5 / 105

x = 0.28

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If the remainder is paid in equal monthly payments of $250. the number of month that the payments must be made is 24.

First step is to find the remainder after down payment

Remainder  = 6500-500

Remainder  = 6000

Now let find the number of monthly payment

Number of monthly payment = Remainder  / Monthly payment

Number of monthly payment = 6000 / 250

Number of monthly payment = 24

Therefore the monthly payment is 24.

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Answer:  30 in.

Step-by-step explanation:

So when you look at the right triangle closely, you can see that the c is the same length as the 30 in. That's why I think it is 30 in. (May be wrong)

[tex]\frac{3}{4}[/tex] of a 6-ounce glass will be drink by Logan in one hour.

What is Quantity?

Quantity is any number or variable and any algebraic combination of other quantities.

Define Average?

The average value in a set of numbers is the middle value, calculated by dividing the total of all the values by the number of values .

Explanation for the answer:

Given time [tex]= \frac{2}{3}[/tex] of hours

                =  [tex]\frac{2}{3}\times 60[/tex] ([tex]\because[/tex] 1hrs = 60min)

                [tex]= \frac{120}{3}[/tex]

               = 40 minutes

Given quantity of water [tex]=\frac{1}{2}\ of\ 6\ ounce[/tex]

                                       [tex]= \frac{1}{2}\times6\\ =3 ounce[/tex]

So,

In 40 mins, water intake is 3 ounce

In 1 min, water intake is [tex]\frac{3}{40}[/tex]

 In 60 mins, water in take is  [tex]\frac{3}{40}\times 60 = 4.5\ ounce[/tex]

Quantity of water intake in 60 mins:

4.5 ounce or 3/4 of 6-ounce glass

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There can be different possible ways in which we can remove the objects and can form possibilities within the rows and columns

What are rows and columns?

Rows and columns are used to properly distinguish categories, classifications, types, etc., when they occur in matrices, spreadsheets, etc. The usage of these words is a bit confusing for most. Rows are a group of cells arranged horizontally to provide uniformity. Columns are a group of cells aligned vertically, and they run from top to bottom. Although the main reason for both rows and columns is to bifurcate groups, categories, and so on,

In the question, It is given that:

There are 16 objects.

and Number of rows = 4;

Number of column = 4;

The task to do is to remove 6, leaving an even number of objects in each row.

So, we can do that in the following manner;

So, we can remove the 2nd object, 4th object, 6th object,8th object,10th object, and 12th object. when we are dealing with rows.

So, we can remove the 2nd object, 4th object, 6th object,8th object,10th object, and 12th object. when we are dealing with the column.

Hence,

There can be different possible ways in which we can remove the objects and can form possibilities.

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Answer:

Carmen will have her loan paid back in 20 months

Answer:

0, 6 * 0,6 = 0.36

Step-by-step explanation:

Keyword is AND.First AND second matches both. It means you need to use *.

The probability of winning both matches is 0.36 or 36%.

It is the chance of an event to occur from a total number of outcomes.

The formula for probability is given as:

Probability = Number of required events / Total number of outcomes.

Example:

The probability of getting a head in tossing a coin.

P(H) = 1/2

We have,

Since the outcome of each match is independent, we can use the multiplication rule of probability to find the probability of winning the next two matches:

P(win both matches) = P(win first match) x P(win second match)

The probability of winning a single match is given as 0.6.

Therefore, the probability of winning the first match is 0.6.

Now, assuming you won the first match, you still have a probability of 0.6 of winning the second match.

Therefore, the probability of winning both matches is:

P(win both matches) = P(win first match) * P(win second match)

= 0.6 x 0.6

= 0.36

Therefore,

The probability of winning both matches is 0.36 or 36%.

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