Please can someone help I have tried many times

Answer:

The given relation R is equivalence relation.

Step-by-step explanation:

Given that:

[tex]((a, b), (c, d))\in R[/tex]

Where [tex]R[/tex] is the relation on the set of ordered pairs of positive integers.

To prove, a relation R to be equivalence relation we need to prove that the relation is reflexive, symmetric and transitive.

1. First of all, let us check reflexive property:

Reflexive property means:

[tex]\forall a \in A \Rightarrow (a,a) \in R[/tex]

Here we need to prove:

[tex]\forall (a, b) \in A \Rightarrow ((a,b), (a,b)) \in R[/tex]

As per the given relation:

[tex]((a,b), (a,b) ) \Rightarrow ab =ab[/tex] which is true.

[tex]\therefore[/tex] R is reflexive.

2. Now, let us check symmetric property:

Symmetric property means:

[tex]\forall \{a,b\} \in A\ if\ (a,b) \in R \Rightarrow (b,a) \in R[/tex]

Here we need to prove:

[tex]\forall {(a, b),(c,d)} \in A \ if\ ((a,b),(c,d)) \in R \Rightarrow ((c,d),(a,b)) \in R[/tex]

As per the given relation:

[tex]((a,b),(c,d)) \in R[/tex] means [tex]ad = bc[/tex]

[tex]((c,d),(a,b)) \in R[/tex] means [tex]cb = da\ or\ ad =bc[/tex]

Hence true.

[tex]\therefore[/tex] R is symmetric.

3. R to be transitive, we need to prove:

[tex]if ((a,b),(c,d)),((c,d),(e,f)) \in R \Rightarrow ((a,b),(e,f)) \in R[/tex]

[tex]((a,b),(c,d)) \in R[/tex] means [tex]ad = cb[/tex].... (1)

[tex]((c,d), (e,f)) \in R[/tex] means [tex]fc = ed[/tex] ...... (2)

To prove:

To be [tex]((a,b), (e,f)) \in R[/tex] we need to prove: [tex]fa = be[/tex]

Multiply (1) with (2):

[tex]adcf = bcde\\\Rightarrow fa = be[/tex]

So, R is transitive as well.

Hence proved that R is an equivalence relation.

The relation R is an equivalence if it is reflexive, symmetric and transitive.

The order to options required to show that R is an equivalence relation are;

Reasons:

Prove that the relation R is reflexive

Reflexive property is a property is the property that a number has a value that it posses (it is equal to itself)

The given relation is ((a, b), (c, d)) ∈ R if and only if a·d = b·c

By multiplication property of equality; a·b = b·a

Therefore;

((a, b), (a, b)) ∈ R

Prove that the relation, R, is symmetric

Given that if ((a, b), (c, d)) ∈ R then we have, a·d = b·c

Therefore, c·b = d·a implies ((c, d), (a, b)) ∈ R

((a, b), (c, d)) and ((c, d), (a, b)) are symmetric.

Prove that R is transitive

Symbolically, transitive property is as follows; If x = y, and y = z, then x = z

From the given relation, ((a, b), (c, d)) ∈ R, then a·d = b·c

Therefore, ((c, d), (e, f)) ∈ R, then c·f = d·e

By multiplication, a·d × c·f = b·c × d·e

a·d·c·f = b·c·d·e

Therefore;

a·f·c·d = b·e·c·d

a·f = b·e

Which gives;

Therefore;

R is an equivalence relation, since R is reflexive, symmetric, and transitive.

Based on a similar question posted online, it is required to rank the given options in the order to show that R is an equivalence relation.

Learn more about equivalent relations here:

https://brainly.com/question/1503196

Answer:

143.81

Step-by-step explanation:

Trapezoid Area

A = 2b/2 * h

A = 9 + 23/2 * 7

A = 32/2 * 7

A = 16 * 7

A = 112

Semi-circle Area

A = πr²/2

A = π4.5²/2

A = π20.25/2

A = 63.62/2

A = 38.81

Total Area

112 + 38.81

143.81

Answer:

Step-by-step explanation: so you calculate how many people ate chicken, beef, fish or are vegetarian then you will add it all together

chicken=128

beef= 80

fish=32

vegetarian=112

128+80+32+112= 352 people ate at the restaurant

Answer:

Altogether, 88 people went to the restaurant.

Step-by-step explanation:

Answer:

C: 38 units

hope this helps!!

Answer:

The two inequalities are;

P ≤ 90e^(0.047t)

P ≤ 270 + 100·t

Step-by-step explanation:

The parameters given for the testing of the new growth inhibitor are;

The growth rate of the bacteria = 4.7% exponentially

The growth inhibitor lowers the growth rate

The population of bacteria after time, t = P

The increase in the number of bacteria per unit time in the 100

The maximum number of bacteria in the standard tube = 270

Therefore, the number of bacteria after the first filling of the tube is P ≤ 270 + 100·t

The equation for exponential growth is [tex]A_0 e^{kt}[/tex]

Where:

A₀ = Initial population = 90

k = Percentage growth rate as percentage

t = Time

The equation for the population of bacteria under the influence of the inhibitor is therefore;

P ≤ [tex]90 \times e^{0.047 \cdot t}[/tex] which is P ≤ 90e^(0.047t).

Answer:

P≤270+100t

P≤90e^(0.047t)

Answer:

[tex]a = 3[/tex]

Step-by-step explanation:

[tex]3 {a}^{2} = 27 \\ \frac{3 {a}^{2} }{3} = \frac{27}{3} \\ {a}^{2} = 9 \\ a = \sqrt{9} \\ a = 3[/tex]

Answer: 9

Step-by-step explanation:

First divide both sides by 3

[tex]a^2=9[/tex]

Then root both sides([tex]\sqrt{a^2}=\sqrt{9}[/tex])

a = 9

Hope it helps <3

Edit: :o this is my 250th answer

Answer:

V = 3534 cm^3

Step-by-step explanation:

The volume of a cylinder is given by

V = pi r^2 h

the radius is 7.5 and the height is 20

V = pi ( 7.5)^2 * 20

V =1125 pi cm^3

Using the pi button for pi

V =3534.291735 cm^3

Rounding to the nearest whole number

V = 3534 cm^3

Answer:

b)3534 cm^3

Step-by-step explanation:

To find the area of a cylinder, you first have to find the area of the base which is in the shape of a circle. The area of a circle is given by the equation πr^2. In this case r, the radius, is 7.5 cm. So plugging in 7.5 for r you get 7.5^2 × π. Plugging in 3.1415 for π you get ~176.671. Now all you do is multiply this by the height, 20cm, and get the answer of ~3534 cm^3.

Answer:

Equation: f(x) = -x² + 3

Step-by-step explanation:

If we want to find the roots/solve for x, we can either graph the problem or use quadratic formula to find when f(x) = 0:

To get the equation of the graph, our parent function is: f(x) = a(x - h)² + k, or f(x) = x². Since we are reflecting over the x-axis with a vertical stretch and vertically moving up to (0, 3), we are modifying a and k only.

Answer:

30 people

Step-by-step explanation:

If you start off with 1/2 a lemon for 6 people, then 1 whole would be 12. 1 1/2 would be 18 people and 2 whole lemons would be 24. so 2 1/2 is 30 people.

Answer:a

Step-by-step explanation:

Answer:

(x + 2)

Step-by-step explanation:

When we factor the expression x² - 8x - 20, we should get (x + 2)(x - 10).

Alternatively, we can use synthetic division or long division to get our answer.

Answer:

x + 2

Step-by-step explanation:

got it right edg '22

Answer:

The volume of the composite figure is 162.7 in^3

Step-by-step explanation:

Here, we have a cylinder placed over a cube

The volume of the cube is L^3

With L being the length of its side = 5

The volume of the cube is 5^3 = 125 in^3

The volume of the cylinder is pi * r^2 * h

with r = 2 in and h = 3 in

The volume of the cylinder = 22/7 * 2^2 * 3 = 37.699 = 37.7 in*3

Total volume is thus;

37.7 + 125 = 162.7 in^3

Answer:

Rational.

Step-by-step explanation:

Irrational numbers are real numbers that can't be written as fractions.

One clue is that the decimal goes on forever (doesn't terminate) without repeating. (pi)

.14 can be written as a fraction: 14/100

Answer:

It's rational

Step-by-step explanation:

Because irrational numbers cannot be written s a fraction and rational numbers can

Answer:

About $3.28

Step-by-step explanation:

Divide 24.33 by 7.4

Answer:

3.28783783784...

Step-by-step explanation:

You're description could turn into 24.33 : 7.4.

You turn 7.4 into 1, and divide 7.4 / 1.

(It is 7.4)

Then, you divide 24.33 / 7.4.

It is 3.28783783784.......

or, If you want you're answer close to an natural number, It is 3.

Answer:

900L per minute

Step-by-step explanation:

1- 70 - 20 = 50

2- in this 50 min the 45000L has been drawned

3- 45000L / 50 = 900L

.. ..

Answer:

Options 2, 4, and 5 are correct (from top to bottom)

Step-by-step explanation:

g(0)=0

g(1)=1

g(-1)=1

g(4)≠-2

g(4)=2

g(1)≠-1

g(1)=1

Options 2, 4, and 5 are correct (from top to bottom)

Answer:

she wills substitute r with 7%.

Step-by-step explanation:

Just did it.

Answer:

R = 7%

Principal (P)

Rate (R)

Time (t)

Step-by-step explanation:

The full intrest rate formula is i=prt

You are looking for r

R is the interest rate 7%

So i = 12,876*7%*3years will be the full equation.

Answer:

factor: 5(2x'y'+3xy)

Step-by-step explanation:

thats for factoring, i didnt know what you needed

Answer:

25xy

Step-by-step explanation:

collect like terms

Answer:

Solution,

Area of rectangle= 524.4 m^2

Length(L)= 6.9 m

Breadth(B)=?

Now,

[tex]area = length \times breadth \\ or \: 524.4 = 6.9 \times b \\ or \: 524.4 = 6.9b \\ or \: b = \frac{524.4}{6.9} \\ b = 76 \: m[/tex]

Again,

Perimeter of rectangle:

[tex]2(l + b) \\ = 2(6.9 + 76) \\ = 2 \times 82.9 \\ = 165.8 \: m[/tex]

Hope this helps...

Good luck on your assignment.....

Answer:

The perimeter of the rectangle is 165.8cm

Step-by-step explanation:

Area of a rectangle = length × width

Area = 524.4m²

length = 6.9m

524.4 = 6.9 × width

width = 524.4 / 6.9

width = 76m

Perimeter of a rectangle =

2(length ) + 2(width)

length = 6.9m

width = 76m

Perimeter = 2( 6.9) + 2(76)

= 13.8 + 152

The final answer is

= 165.8cm

Hope this helps you

Answer:

[tex]$\left(\frac{x}{2} + 3 y\right)^{4}=\frac{x^{4}}{16} + \frac{3}{2} x^{3} y + \frac{27}{2} x^{2} y^{2} + 54 x y^{3} + 81 y^{4}$[/tex]

Step-by-step explanation:

[tex]$\left(\frac{1}{2}x+3y \right)^4=\left(\frac{x}{2}+3y \right)^4\\$[/tex]

Binomial Expansion Formula:

[tex]$(a+b)^n=\sum_{k=0}^n \binom{n}{k} a^{n-k} b^k$[/tex], also [tex]$\binom{n}{k}=\frac{n!}{(n-k)!k!}$[/tex]

We have to solve [tex]$\left(\frac{x}{2} + 3 y\right)^{4}=\sum_{k=0}^{4} \binom{4}{k} \left(3 y\right)^{4-k} \left(\frac{x}{2}\right)^k$[/tex]

Now we should calculate for [tex]k=0, k=1, k=2, k=3 \text{ and } k =4;[/tex]

First, for [tex]k=0[/tex]

[tex]$\binom{4}{0} \left(3 y\right)^{4-0} \left(\frac{x}{2}\right)^{0}=\frac{4!}{(4-0)! 0!}\left(3 y\right)^{4} \left(\frac{x}{2}\right)^{0}=\frac{4!}{4!}(81y^4)\cdot 1 =81 y^{4}$[/tex]

It is the same procedure for the other:

For [tex]k=1[/tex]

[tex]$\binom{4}{1} \left(3 y\right)^{4-1} \left(\frac{x}{2}\right)^{1}=54 x y^{3}$[/tex]

For [tex]k=2[/tex]

[tex]$\binom{4}{2} \left(3 y\right)^{4-2} \left(\frac{x}{2}\right)^{2}=\frac{27}{2} x^{2} y^{2}$[/tex]

For [tex]k=3[/tex]

[tex]$\binom{4}{3} \left(3 y\right)^{4-3} \left(\frac{x}{2}\right)^{3}=\frac{3}{2} x^{3} y$[/tex]

For [tex]k=4[/tex]

[tex]$\binom{4}{4} \left(3 y\right)^{4-4} \left(\frac{x}{2}\right)^{4}=\frac{x^{4}}{16}$[/tex]

You can perform the calculations, I will not type everything.

The answer is the sum of elements calculated.

Just organizing:

[tex]$\left(\frac{x}{2} + 3 y\right)^{4}=\frac{x^{4}}{16} + \frac{3}{2} x^{3} y + \frac{27}{2} x^{2} y^{2} + 54 x y^{3} + 81 y^{4}$[/tex]

Answer:  [tex]\bold{\dfrac{1}{16}x^4 + \dfrac{3}{2}x^3y + \dfrac{27}{2}x^2y^2 +54xy^3+81y^4}[/tex]

Step-by-step explanation:

                     Binomial Tree

n=0                         1

n=1                      1      1

n=2                  1    2     1

n=3               1    3    3     1

n=4            1    4    6    4    1

Using the Binomial Theorem

[tex]\bigg(\dfrac{1}{2}x+3y\bigg)^4\\\\\\=1\bigg(\dfrac{1}{2}x\bigg)^4(3y)^0\quad \rightarrow \quad \dfrac{1}{16}x^4\\\\+4\bigg(\dfrac{1}{2}x\bigg)^3(3y)^1\quad \rightarrow \quad \dfrac{3}{2}x^3y\\\\+6\bigg(\dfrac{1}{2}x\bigg)^2(3y)^2\quad \rightarrow \quad \dfrac{27}{2}x^2y^2\\\\+4\bigg(\dfrac{1}{2}x\bigg)^1(3y)^3\quad \rightarrow \quad 54xy^3\\\\+1\bigg(\dfrac{1}{2}x\bigg)^0(3y)^4\quad \rightarrow \quad 81y^4[/tex]

______________________

[tex]= \dfrac{1}{16}x^4 + \dfrac{3}{2}x^3y + \dfrac{27}{2}x^2y^2 +54xy^3+81y^4[/tex]

Answer: 343 cm³

Step-by-step explanation:

The surface area of a cube is 6s^2, where s is the side length of a square.  Thus, first do 294/6 to get 49.  Then take the square root of 49 to get that each side of the cube is 7.  The volume of a cube is s^2, so simply do 7*7*7 to get that the volume of the cube is 343cm^3

Hope it helps <3

Answer:

V =343 cm^3

Step-by-step explanation:

The surface area of a cube is given by

SA = 6s^2 where s is the side length

294 = 6s^2

Divide by 6

294 / 6 = s^2

49 = s^2

Take the square root of each side

sqrt(49) = sqrt(s^2)

7 =s

The volume of a cube is

V = s^3

V = 7^3

V =343 cm^3

Answer:

Step-by-step explanation:

A square has equal sides. Let x represent the length of each side of the square carpet. The diagram representing the room and the carpet is shown in the attached photo. Therefore, the length of the room would be (x + 2)m while the width of the room would be (x + 1)m

Since the area of the room is 56m², it means that

(x + 2)(x + 1) = 56

x² + x + 2x + 2 = 56

x² + 3x + 2 - 56 = 0

x² + 3x - 54 = 0

x² + 9x - 6x - 54 = 0

x(x + 9) - 6(x + 9) = 0

x - 6 = 0 or x + 9 = 0

x = 6 or x = - 9

Since the dimension of the carpet cannot be negative, then x = 6

The dimension of the carpet is 6m × 6m

Answer:

A y=1/2x(powerof)2+5

B 17.5

C x=√42 or x=−√42

Step-by-step explanation:

Answer:

a. y = x^2 + 10

b. when x=5,   y  = 35

c. when y = 26,   x =  +4 or -4

Step-by-step explanation:

Given

y = k (x^2/2 + 5), and

(2,14) is on the curve.

Solution:

Substitute x=2 and y=14 in the above equation

14 = k (2^2/2 + 5)

14 = k (2+5)

14 = 7k

k = 14/7 = 2

a. equation connecting x and y is

   y = 2 (x^2/2 + 5), or

   y = x^2 + 10

b. when x=5

   y = 5^2 + 10 = 25 + 10 = 35

c. when y = 26

  26 = x^2 + 10

  x^2 = 26-10 = 16

  x= sqrt(16) = +4 or -4

Answer:

(2)They are perpendicular.

Step-by-step explanation:

Answer:

Colin got £126

Step-by-step explanation:

Here we want to know how much Colin got from the sharing.

We can collapse the ratio to mean;

Colin : Caroline + Sarah

= 9:1 + 1 = 9:2

So total ratio is 9 + 2 = 11

If Caroline and Sarah got £28 we need to find the total money shared

Let the total money shared be £x

Thus;

2/11 * x = 28

2x = 11 * 28

x = (11 * 28)/2

x = 11 * 14 = £154

So the amount of money Colin got would be;

£154 - £28 = £126

A=4[tex]\pi -8[/tex]

that is your answer :-)

Answer:

[tex]A = 4\pi - 8[/tex]

Step-by-step explanation:

ody

Answer:

a) 12 (Simply divide 4800/5 to get 960.  Then divide 960/80 to get 12)

b) 2100 (Simply multiply 12 by 25 by 7)

Hope it helps <3

Answer:

Second choice.

f(x) = 1/2(x - 6)^2 + 3/2.

Step-by-step explanation:

The distance of a point  (x, y) from the focus = the distance of the point from the directrix, so:

(x - 6)^2 + (y - 2)^2 = (y - 1)^2

x^2 - 12x + 36 + y^2 - 4y + 4 = y^2 - 2y + 1

x^2 -12x + 39 = 2y

y = f(x) = 1/2 (x^2 - 12x + 39)

I see you want the answer in vertex for so it is:

f(x)  = 1/2 [ (x - 6)^2 - 36)  + 39)

f(x)  = 1/2(x - 6)^2 + 3)

f(x) = 1/2(x - 6)^2 + 3/2.

A parabola is a plane that is approximately U-shaped.

The equation of the parabola is: [tex]\mathbf{y = \frac{1}{2}(x - 6)^2 + \frac 32}[/tex]

The given parameters are:

[tex]\mathbf{Focus = (6,2)}[/tex]

[tex]\mathbf{Directrix: y = 1}[/tex]

First, equate the directrix to 0

[tex]\mathbf{y - 1 = 0}[/tex]

The equation is then calculated as:

[tex]\mathbf{(x - a)^2 + (y - b)^2 = (y- 1)^2}[/tex]

Where:

[tex]\mathbf{(a,b) = (6,2)}[/tex]

So, we have:

[tex]\mathbf{(x - 6)^2 + (y - 2)^2 = (y- 1)^2}[/tex]

Expand

[tex]\mathbf{x^2 - 12x +36 + y^2 - 4y + 4 = y^2 - 2y + 1}[/tex]

Subtract y^2 from both sides

[tex]\mathbf{x^2 - 12x +36 - 4y + 4 =- 2y + 1}[/tex]

Collect like terms

[tex]\mathbf{x^2 - 12x +36 + 4 - 1 =4y - 2y}[/tex]

[tex]\mathbf{x^2 - 12x +39 =2y}[/tex]

Divide through by 2

[tex]\mathbf{y = \frac{1}{2}(x^2 - 12x +39)}[/tex]

Express 39 as 36 + 3

[tex]\mathbf{y = \frac{1}{2}(x^2 - 12x +36 + 3)}[/tex]

Factor out 3/2

[tex]\mathbf{y = \frac{1}{2}(x^2 - 12x +36) + \frac 32}[/tex]

Expand the bracket

[tex]\mathbf{y = \frac{1}{2}(x^2 - 6x - 6x +36) + \frac 32}[/tex]

Factorize

[tex]\mathbf{y = \frac{1}{2}(x(x - 6) - 6(x -6)) + \frac 32}[/tex]

Factor out x - 6

[tex]\mathbf{y = \frac{1}{2}((x - 6) (x -6)) + \frac 32}[/tex]

Express as squares

[tex]\mathbf{y = \frac{1}{2}(x - 6)^2 + \frac 32}[/tex]

Hence, the equation of the parabola is: [tex]\mathbf{y = \frac{1}{2}(x - 6)^2 + \frac 32}[/tex]

Read more about equations of parabola at:

https://brainly.com/question/4074088

Answer:

110

Step-by-step explanation:

There are 200 people in a cinema- This is our total amount.

25 % of the people are men.

.25 times 200= 50

There are 50 men.

1/5 (20%) of the people are women.

.2 times 200 = 40

There are 40 women.

50+40 = 90

There are 90 adults in the cinema.

If there are 200 total people in the cinema, and 90 of them are adult, then 110 of them are children.

The percentage is 55%.

The simplified fraction is 11/20.

The decimal is .55