Answer:
u should put this also in English then type it in so it will translate
Let $n$ be a positive integer. (a) Prove that \[n^3 = n + 3n(n - 1) + 6 \binom{n}{3}\]by counting the number of ordered triples $(a,b,c)$ of positive integers, where $1 \le a,$ $b,$ $c \le n,$ in two different ways. (b) Prove that \[\binom{n + 2}{3} = (1)(n) + (2)(n - 1) + (3)(n - 2) + \dots + (k)(n - k + 1) + \dots + (n)(1),\]by counting the number of subsets of $\{1, 2, 3, \dots, n + 2\}$ containing three different numbers in two different ways.
Answer:
Description of the given points can be defined as follows:
Step-by-step explanation:
In points A, If b is less than a and c. so, it calls the smiley face (a, b , c), so we'll have a smiling smile whenever we create a chart! And if b is bigger then a and c, then it should be an angry face, although when we switch the head inside out, they get a grumpy face.
In point b, the smirks, which including a greater than b and c, then it is the neutral faces like a is equal to and b equal to c , it can also be seen in certain forms of faces. When the facial is positive, therefore b and b is similar to c. because when we pick a, b and c, but there's a choice of n are neutral.
Its quantity of scowls has been counted. There are many n options to choose a or n-1 forms of picking b. Each value that we can choose for the could also have been the price of b or c. There is also multiplication by 3. Thus 3n(n-1) scowls were present.
A number of happy face faces we note now. There will be n options for such a then n – 1 options for b, but n – 2 options for c. There were the happy faces of n(n-1)(n-2) = 3C(n,3). There are many grumpy face faces of the configuration of 3C(n,3).
Thus, n^3 = n + 3n(n – 1)+ 6C(n,3) was its total amount of faces.
(b) We can select two groups of 2 categories one at two numbers to choose three numbers and the other with one group. Its total number of n+2 can be divided into two groups.
First, there are many two numbers with one group, then n number in another one. This makes up n + 2 number of all. C(2,2) = 1 represents selecting two digits from the two sets. There are many C(n,1) = n forms to select a single organization amount. Which offers us a first 1*n term.
2. A curve has equation y = x2 – 2x - 3. A point moves along the curve in such a way that at P
the y coordinate is increasing at 4 units per second and the x coordinate is increasing at 6
units per second. Find the x coordinate of P.
[3]
Answer:
The x coordinate of P is [tex]\frac{4}{3}[/tex].
Step-by-step explanation:
Let is find the rate of change of the equation in time, which consists in a composite differentiation. That is:
[tex]\frac{dy}{dt} = 2\cdot x \cdot \frac{dx}{dt} -2\cdot \frac{dx}{dt}[/tex]
According to the statement of the problem, these variables are known:
[tex]\frac{dx}{dt} = 6[/tex] and [tex]\frac{dy}{dt} = 4[/tex]
Hence, the x coordinate of P is found by direct substitution:
[tex]4 = 2\cdot x \cdot (6)-2\cdot (6)[/tex]
[tex]4 = 12\cdot x -12[/tex]
[tex]x = \frac{4}{3}[/tex]
The x coordinate of P is [tex]\frac{4}{3}[/tex].
Use the concept of slope to find t such that the three points are collinear. (-8,5) (0,t) (2,-1)
Answer:
t = [tex]\frac{1}{5}[/tex]
Step-by-step explanation:
Since the points are collinear they lie on the same line.
Thus the slopes between any of the 3 points are equal.
Calculate the slope m using the slope formula
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = (- 8, 5) and (x₂, y₂ ) = (2, - 1)
m = [tex]\frac{-1-5}{2+8}[/tex] = [tex]\frac{-6}{10}[/tex] = - [tex]\frac{3}{5}[/tex]
Repeat using
(x₁, y₁ ) = (- 8, 5 ) and (x₂, y₂ ) = (0, t) and equate to previous m
m = [tex]\frac{t-5}{0+8}[/tex] = [tex]\frac{t-5}{8}[/tex] = - [tex]\frac{3}{5}[/tex] ( cross- multiply )
5(t - 5) = - 24 , that is
5t - 25 = - 24 ( add 25 to both sides )
5t = 1 ( divide both sides by 5 )
t = [tex]\frac{1}{5}[/tex]
The bottom of the swimming pool seem to be raised 3m above with water of refractive index 4/3. The depth of water is:
A. 12m
B. 29m
C. 4m
D. 6m
(will mark the brainliest with explanation)
a circular hall has a hemispherical roof. the greatest height is equal to the internal diameter .if the capacity of the hall is 43510 m^3 ,then the area of the floor is
This building is basically a cylinder with a hemisphere on top. Let d be the diameter of the hemispherical roof. This is also the height of the entire building as the greatest height is this value (which is located at the center of the building)
The hemisphere itself is r = d/2 meters high, which is the radius of the roof. The cylinder portion's height must be d - r = d - d/2 = 2d/2 - d/2 = d/2 = r meters. So basically the cylinder and the hemisphere both have the same height of r.
At the same time, the cylinder and hemisphere also have the same radius r, or else the roof wouldn't fit on the cylinder.
------------------------------
Volume of cylinder = pi*r^2*h = pi*r^2*r = pi*r^3
Note how I replaced h with r and simplified.
Also,
Volume of hemisphere = (1/2)*(volume of sphere)
Volume of hemisphere = (1/2)*( (4/3)*pi*r^3 )
Volume of hemisphere = (2/3)*pi*r^3
------------------------------
Add the two volume expressions
total volume = (volume of cylinder) + (volume of hemisphere)
total volume = (pi*r^3) + ( (2/3)*pi*r^3 )
total volume = (3/3)pi*r^3 + (2/3)pi*r^3
total volume = (5/3)pi*r^3
------------------------------
Set this equal to 43510 and solve for r
(5/3)pi*r^3 = 43510
pi*r^3 = (3/5)*43510
pi*r^3 = 26106
r^3 = 26106/pi
r = (26106/pi)^(1/3)
r = 20.2549023450428
The building has a radius of approximately 20.2549023450428 meters
------------------------------
We can now compute the area of the circular floor
area = pi*r^2
area = pi*(20.2549023450428)^2
area = 1,288.87316044698
Answer: approximately 1288.87316044698 square metersRound this however you need to
solve for x 4(x+2)=48
Answer: 10
Step-by-step explanation:
4(x+2)=48
4x+8=48
4x=40
x=10
Answer:
x=10
Step-by-step explanation:
4(x+2)=48
Divide each side by 4
4/4(x+2)=48/4
x+2 = 12
Subtract 2 from each side
x+2-2= 12-2
x = 10
Work out the mean for the data set below: 3, 5, 4, 3, 5, 6 Give your answer as a fraction. answer
Answer:
4 1/3
Step-by-step explanation:
3 + 5 + 4 + 3 + 5 + 6 = 26
26/6 = 4 2/6 (4 1/3)
Answer:
13/3
Step-by-step explanation:
To find the mean, add up all the numbers and divide by the number of terms
( 3+5+4+3+5+6) /6
26/6
Divide top and bottom by 2 to simplify the fraction
13/3
The sum of two numbers, x and y, Is 12. The difference of x and two times y is 6. What are the values of x and y?
A. x=8, y= 4
B.x= 10, y= 2
C. x = 18, y=-6
D. X= 20, y=-8
Answer:
B. x = 10, y= 2
Step-by-step explanation:
10 plus 2 is 12 and when 2 is doubled and then subtracted from 10, the difference is 6
11.Area of Triangle is 18 cm sq. and Sum of Base and Altitude is 12 cm. The Base and Altitude are:
(1 Point)
4 , 8 4 cm, 8 cm
8, 4 8cm, 4 cm
6 , 6 6 cm, 6 cm
10 , 2 10 cm, 2 cm
Answer:
base and altitude both are 6 cmand 6cm
D( Geese fly in V formation. The V forms a right angle that has 16 geese on 1 side and 12 geese on the other side. How many gesse would fill in the gap between the ends of each sides of the V formation?
Answer:
20 gesse will fill the gap
Explanation:
We were told that the V forms a right angle which means the angle is at 90 degrees.
From trigonometry, for a right angle triangle we have the opposite, hypotenose and adjacent, then here the 12 side is the opposite and 16 sides is the adjacent, then the hypotenose will be the gap we are looking for using below expression
a²+ b²= c²
So,
12²+ 16²= c²
144 + 256 = c²
c=√(144 + 256)
c = √400
c=20
Therefore, 20 gesse will fly in the missing gap of the V formation.
CHECK THE ATTACHMENT FOR THE TRIANGLE
BEST OF LUCK
Someone pls help me . I will mark you brainliest !! thank you sm .
Answer:
first one is 27.89, the second is 20.
Step-by-step explanation:
1. So the 340 dollars is determined by 9.50 multiplied by the amount of hours you show up (which we will call x), plus the 75 dollars.
Your equation will be set up like this : 9.50x +75 = 340
So, to get x, we must isolate it. so subtract 75 from both sides
9.50x +75 -75 = 340 -75 9.50x = 265
Now, since we know that 9.50 multiplied by x equals 265, to isolate and find out x (the hours worked during the pay period), we divide both sides by 9.50
9.50x/9.50 = 265/9.50 so, x = 27.89473684, but based off of the answers there, you would just round to x = 27. 89 hours worked.
2. So now the 120 chips are determined by 6 chips multiplied by the minutes, since 6 chips are eaten every minute, with the minutes represented as x, like this: 6x = 120
So this time, you don't subtract or add anything, you would just divide by 6 to isolate x.
6x/6 = 120/6 so, x = 20 minutes.
A dolphin is swimming with her friend. The dolphin jumps to a height of 4.5 meters above the surface of the water as her friend swims 9.8 meters directly below her.
Answer:
-5.3 meters
The dolphin's friend is 5.3 meters below the water surface
Step-by-step explanation:
Complete question below:
A dolphin is swimming with her friend. The dolphin jumps to a height of 4.54 meters above the surface of the water as her friend swims 9.8 meters directly below her. What is the position of the dolphin's friend relative to the surface of the water?
Solution
The dolphin jumps to a height of 4.5 meters above the surface of the water
Her friend swims directly 9.8 meters below her
The position of the dolphin's friend relative to the surface of the water= dolphins position above the surface of the water - her friend's position below her
=4.5 meters - 9.8 meters
= -5.3 meters
-5.3 meters means below the water surfaces
This means, the dolphin's friend is 5.3 meters below the water surface
How to do this question plz answer me step by step plzz plz
Answer:
4 cm
Step-by-step explanation:
Volume of milk
LBH
L= 8, B= 5 and H =12
5×8×12=480
After rotation
L= 8, B=15 and H=x
V=LBH
480=8×15×x
480=120x
x=4cm
Answer:
The depth of the milk is 4cm when turned
Step-by-step explanation:
First we need to figure out how much milk is inside the container. We can do this by finding the volume it takes up. The milk's depth is 12cm so the height is 12 instead of 15. The length and width remain the same (5 and 8)
5x8x12=480 cm^3
The volume of the milk is 480, so when the carton is turned, the milk's volume still is the same
When it is turned, the base changes. Now it is 8 and 15 for the length and width. We just need to find the height.
8x15xh=480
120h=480
h=4
The depth of the milk is 4cm when turned
17. a(y + c) = b(y - c)
How do I isolate y?
Expand the products on both sides:
[tex]a(y+c)=b(y-c) \implies ay+ac=by-bc[/tex]
Move all terms containing y to one side:
[tex]ay+ac=by-bc \implies ay-by=-ac-bc[/tex]
Factor out y :
[tex]ay-by=-ac-bc \implies y(a-b)=-ac-bc[/tex]
Solve for y :
[tex]y(a-b)=-ac-bc \implies y=\dfrac{-ac-bc}{a-b}=-\dfrac{c(a+b)}{a-b}=\dfrac{c(a+b)}{b-a}[/tex]
Melody wants to buy a present for her friend for her birthday. She wants to purchase a CD that costs $18. She thought she had $20 in her bank account, but she really has $16. What was her percent error?
Answer: 20%
Step-by-step explanation: $20-$16=$4. 4/20=1/5 or 20%.
Answer: Melody's percent error was 20%
Step-by-step explanation:
20-16=4
4/20=1/5
I promise i will mark as brainiest
Answer:
A
Step-by-step explanation:
[tex] \frac{2003}{n} = z + \frac{23}{n} [/tex]
where z is an integer
[tex]2003 = nz + 23[/tex]
[tex]nz = 1980[/tex]
[tex]nz = {2}^{2} \times {3}^{2} \times 5 \times 11[/tex]
possible values of n
n= {1980, 990, 660, 495, 396, 330, 198, 180, 165, 132, 99, 90, 60, 45, 36, 30, 20, 18, 15, 5, 3}
cardinality of n=21
A car is traveling on a highway. The distance (in miles) from its destination and the time (in hours) is given by the equation d = 420 minus 65 t. What is the practical meaning of the d-intercept? a. Initially the car is 355 miles from its destination. b. Initially the car is 420 miles from its destination. c. Initially the car is 65 miles from its destination. d. Initially the car is 485 miles from its destination.
Answer:
the correct answer is b. Initially the car is 420 miles from its destination.
Step-by-step explanation:
Given the following angles, what ray is the common side of ZCFD and ZDFE?
D
E
0
Ray FD
Ray FE
Ray FC
Answer:
ray df or ray fd because both of these letters are consecutive in both of the angles.
Step-by-step explanation:
Answer:
Answer is Ray FD
Step-by-step explanation:
Given the following angles, what ray is the common side of ∠CFD and ∠DFE?
A. Ray FC
B. Ray FE
C. Ray FD
HELP HELP HELP Sally can paint a room in 4 hours. Joe can paint a room in 6 hours. How
long will it take if they paint the room together? I’m not sure if it’s 1.4
Answer:
2 hrs, 24 min
Step-by-step explanation:
Sally: in one hour, she can paint 1/4 of the room.
Joe: in one our, he can paint 1/6 of the room
Hour one: 1/4+1/6=3/12+2/12=5/12
1÷5/12=1*12/5=12/5
12/5= 2 & 2/5 hours, or 2.4 hours, or 2 hrs 24 minutes
Answer: 2.4 hours
Step-by-step explanation:
1/4 1/6
LCM
3/12+2/12=5/12 repricical 12/5 =2.4
In the first quadrant you start at 5, 6 and move 4 units down. What point will you end up at? Thanks for your help! - Someone who's better at English than math
Answer:
(5, 2)
Step-by-step explanation:
(5, 6) go down 4 units means subtract 4 from the y
(5, 2)
The point to end up will be (5, 2).
What is Coordinates?
A pair of numbers which describe the exact position of a point on a cartesian plane by using the horizontal and vertical lines is called the coordinates.
Given that;
In the first quadrant you start at (5, 6 ) and move 4 units down.
Now,
Since, In the first quadrant you start at 5, 6 and move 4 units down.
Hence, The end up point = (5, 6 - 4)
= (5, 2)
Thus, The point to end up will be (5, 2).
Learn more about the coordinate visit:
https://brainly.com/question/18269861
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Find the constant of proportionality (r) in the equation y = r x
Answer:
r = 11Step-by-step explanation:
y = r x
r is the constant of proportionality
To find r pick any values of x and y provided and substitute it into the above formula and solve for r.
That's
using
x = 2
y = 22
We have
22 = 2r
Divide both sides by 2
r = 11Therefore the constant of proportionality is 11
Hope this helps you
Suppose that F(x) = x? and g(x) = -3x? Which statement best compares the
graph of G(x) with the graph of F(x)?
Answer:
flipped over the x-axis and stretched verticallyStep-by-step explanation:
Multiplying y by a value greater than 1 results in a vertical stretch. When the sign of it is negative there is a reflection over the x-axis. The appropriate choice is shown below.
__
The second attachment shows how the graph is flipped and stretched.
earth is 93 million miles from the sun, while mars is 142 million miles from the sun. Theoretically, what is the closest distance mars could be to earth
Answer:
169.74
Step-by-step explanation:
this problem is like a triangle, the sun, mars, and earth are the three points, so you just use a^2 + b^2 = c^2 so basically
93^2 + 142^2 = c^2
8649 + 20164 = 28813
28813 square root = 169.74
Will give Brainliest, Please show work.
Answer:
Hi, there!!
Hope you mean the answers in the solution.
Hope it helps...
Answer:
Step-by-step explanation:
7)
JKLM is a isosceles trapezium.
KL // JM
∠K + ∠J = 180 {Co interior angles}
50 +∠J = 180
∠J = 180 - 50
∠J = 130
As it is isosceles, non parallel sides KJ = LM &
∠L = ∠K
∠L = 50
∠M = ∠J
∠M = 130
8)JKLM is a isosceles trapezium.
KL // JM
∠K + ∠J = 180 {Co interior angles}
100 +∠J = 180
∠J = 180 - 100
∠J = 80
As it is isosceles, non parallel sides KJ = LM &
∠L = ∠K
∠L = 100
∠M = ∠J
∠M = 80
Question 13 of 25
Which of the following is a correct name for a side of the given angle?
D
E
A. Point E
B. ED
C. DE
D. Point D
Evaluate sin^-1 1/2 . Round your answer to the nearest hundredth.
Answer:
30.00Step-by-step explanation:
Given the expression [tex]sin^{-1} 1/2[/tex], the following steps must be taken to evaluate the expression.
[tex]Let\ y = sin^{-1}1/2[/tex]
[tex]y = sin^{-1} 0.5[/tex]
From the calculator, the value of y wil give;
[tex]y = 30\\\\y = 30.00 (to\ the \ nearest \ hundredth)[/tex]
Hence [tex]sin^{-1} 0.5 = 30.00[/tex].
Answer:
Step-by-step explanation:
The answer is 0.52
Hope that helped
10201 soldiers have queued up for an attack such that the number of queues is equal to number of the soldiers in each queue. Find number of soldiers in queue.
Answer:
101
Step-by-step explanation:
Given the following :
Number of soldiers = 10201
They are queued such that the number of queues = number of soldiers in each queue
Let number of queues = q
Therefore, if number of queues equals number of soldiers per Q,
Then ;
q × q = 10201
q^2 = 10201
Take the square root of both sides
q = √10201
q = 101
Number of soldiers per queues = 101
2) In 1000 sq. meter of land a farmer cultivated 765 kg of rice with the wastage of 23.5%. I) Find the weight of the wastage. II) Find the weight and percentage of rice cultivated. 3) If the area has been increased 40 times in size, how much rice will be cultivated (excluding the wastag
Answer:
Weight of wastage=179.775kg
weight of rice cultivated= 585.225 kg
percentage of rice cultivated=76.5%
Step-by-step explanation:
Area of land=100 square meters
Cultivated rice=765kg
Wastage=23.5%
1) Weight of the wastage=23.5% of 765kg
=23.5/100 × 765
=17977.5 / 100
=179.775 kg
2) Weight and percentage of rice cultivated.
weight of rice cultivated = 765 kg - 179. 775 kg
= 585.225 kg
percentage of rice cultivated = 100 - 23.5
= 76.5%
3) if area is increased 40 times in size
New area=1000 square meters × 40
=40,000 square meters
Cultivated rice= 765kg × 40
=30,600 kg
Cultivated rice excluding wastage=585.225 kg × 40
=23,409 kg
Plz help ASAP ill give brainliest What is 600 square
Answer:
360,000
Step-by-step explanation:
When you square something you multiply it by itself. With that in mind, 600 square or 600^2 would be 600x600 which equals 360,000. Please mark as brainliest.
Insert 2 sets of parentheses to make each sentence true: 2 x 14 – 9 – 17 – 14 = 7 (2 x 14) – 9 – (17 – 14) = 7 2 x (14 – 9) + (– 17 – 14) = 7 (2 x 14) – (9 – 17) – 14 = 7 2 x (14 – 9) – (17 – 14) = 7
Answer:
2 × (14 – 9) – (17 – 14) = 7
Step-by-step explanation:
Evaluate the choices to see which is true.
(2 x 14) – 9 – (17 – 14) = 7 ⇒ 28 -9 -3 ≠ 7
2 x (14 – 9) + (– 17 – 14) = 7 ⇒ 2(5) +(-31) ≠ 7
(2 x 14) – (9 – 17) – 14 = 7 ⇒ 28 -(-8) -14 ≠ 7
2 x (14 – 9) – (17 – 14) = 7 ⇒ 2(5)- 3 = 7 . . . . true
