The closed form sum of
$$12 \left[ 1^2 \cdot 2 + 2^2 \cdot 3 + \ldots + n^2 (n+1) \right]$$
for $n \geq 1$ is $n(n+1)(n+2)(an+b).$ Find $an + b.$
![The Closed Form Sum Of$$12 \left[ 1^2 \cdot 2 + 2^2 \cdot 3 + \ldots + N^2 (n+1) \right]$$for $n \geq](https://brainimage.s3.us-east-005.backblazeb2.com/contents/attachments/4OZsr5wDNMA2j4ncbnzkm2li3bu13Nvi.png)
Answers
Perhaps you know that
[tex]S_2 = \displaystyle\sum_{k=1}^n k^2 = \frac{n(n+1)(2n+1)}6[/tex]
and
[tex]S_3 = \displaystyle\sum_{k=1}^n k^3 = \frac{n^2(n+1)^2}4[/tex]
Then the problem is trivial, since
[tex]\displaystyle\sum_{k=1}^n k^2(k+1) = S_2 + S_3 \\\\ = \frac{2n(n+1)(2n+1)+3n^2(n+1)^2}{12} \\\\ = \frac{n(n+1)\big((2(2n+1)+3n(n+1)\big)}{12} \\\\ = \frac{n(n+1)\big(4n+2+3n^2+3n\big)}{12} \\\\ = \frac{n(n+1)(3n^2+7n+2)}{12} \\\\ = \frac{n(n+1)(3n+1)(n+2)}{12}[/tex]
Then
[tex]12\bigg(1^2\cdot2+2^2\cdot3+3^2\cdot4+\cdots+n^2(n+1)\bigg) = n(n+1)(n+2)(3n+1)[/tex]
so that a = 3 and b = 1.
Related Questions
The number of bags of Brand Y dog food sold on these five days was 175. Which bar represents the data for Day 5 for Brand Y?
Answers
Answer:
30
Step-by-step explanation:
In the circle below, if arc AB = 48°, and arc CD = 122°, find the measure of < CPD.
Select one:
a. 170°
b. 122
C. 85 °
d. 48
Answers
Answer:
C
Step-by-step explanation:
trust me
3. the third one please answer ASAP write it on paper, please
Answers
To 4/5+3/15-2/3
Answer:
1/3
Step-by-step explanation:
We have to make the denominator of all fractions to be 15:
Multiply both the 4 and the 5 in 4/5 by 3 to get 12/15.
Nothing has to be done to 3/15.
Next, multiply both the -2 and the 3 in -2/3 by 5 to get -10/15.
Solve:
12/15 + 3/15 - 10/15 = 5/15.
5/15 further simplifies to 1/3.
The final answer is 1/3.
Use the graph to find the constant of proportionality (unit rate)
Answers
Answer:
9) 10
10) 5
Step-by-step explanation:
HELP!!! I will give brainliest, 25 points!!
Mu Alpha Theta, a math honorary club, wants to raise money. The club plans to sell cards and bouquets of flowers for Valentine's Day. Cards cost the club $2 each; bouquets cost the club $3.50 each. Mu Alpha will sell the cards for $6 each, and the flowers for $8 each. The club can spend $360 to buy the cards and the flowers. It wants to collect $900 from its sales. Which linear equation represents this scenario?
A. 2x + 3.5y =360; 6x -8y =900
B. 2x + 3.5y = 360; 8x + 6y = 900
C. 2x - 3.5y = 360; 6x + 8y = 900
D. 2x + 3.5y = 360; 6x + 8y = 900
E. 2x + 6y = 360; 3.5x + 8y = 900
F. No equation.
Answers
Answer:
900
Step-by-step explanation:
2x+3.5y=360 and 6x+8y=900 are two linear equation that represents the given scenario.
We need to find the linear equations for the given situation.
What is the simultaneous equation?Equations involving two or more unknowns that are to have the same values in each equation.
Let the number of cards be x and the number of flowers be y.
Cards cost the club $2 each; bouquets cost the club $3.50 each. The club can spend $360 to buy the cards and the flowers.
Now, 2x+3.5y=360
Mu Alpha will sell the cards for $6 each, and the flowers for $8 each. It wants to collect $900 from its sales.
Now, 6x+8y=900
Therefore, 2x+3.5y=360 and 6x+8y=900 are two linear equation that represents the given scenario.
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2.5 kg of oranges cost $ 1.40, what is the cost of
1 kg of orange?
Answers
Work:
2.5/1.40 = 1/x
- Cross-multiply
2.5x ÷ 2.5 = x
1.40 ÷ 2.5 = 0.56
x = 0.56
Honestly, I'm trying my best to solve this but my Math XL is being so rude.
Answers
==============================================================
Explanation:
T is the midpoint of PQ, which means T splits PQ into two equal parts. Those parts being PT and TQ.
Set them equal to each other and solve for x.
PT = TQ
3x+7 = 7x-9
3x-7x = -9-7
-4x = -16
x = -16/(-4)
x = 4
So,
PT = 3x+7 = 3*4+7 = 19
TQ = 7x-9 = 7*4-9 = 19
Both PT and TQ are 19 units long to help confirm the answer.
Please Help
The students in a high school are being randomly split into focus and accountability groups that meet each morning for the first fifteen minutes of the school day. Each group contains four students, selected regardless of gender or grade level.
In order to explore the composition of the groups with regard to grade level, you have decided to conduct a simulation using colored discs. Since the number of students in each grade level is about the same, you put the same number of four different colored discs in a bag: red, blue, green, and yellow. You decide that red (r) represents the freshmen, blue (b) represents the sophomores, green (g) represents the juniors, and yellow (y) represents the seniors.
Next, you randomly select one disc from the bag, record the color, and put the disc bag in the bag. You do the same thing three more times to represent one group. Then, you complete this entire process twenty-five times, as shown below.
Based on the results of the simulation, the chances of a group having at least one senior is:
likely
unlikely
neither unlikely or likely
Answers
19/25 which is likely
count the ones with y and put that over 25
helphelphelphelphelphelp
Answers
Answer:
see image
Step-by-step explanation:
Geometry, please answer question ASAP
Answers
Answer:
144.5 in ^2
Step-by-step explanation:
The area of a trapezoid is given by
A = 1/2 (b1+b2) h where the b1 and b2 are the lengths of the bases and h is the height
A = 1/2 ( 9.7+24.3) * 8.5
= 1/2 ( 34)*8.5
=144.5
when Rons truck was full, it weighed 7.5 tons. The weight he carried at that time was 3.25 tons. How many tons does Ron's truck weigh when it is empty?
Answers
7.5-3.25=4.25 tons.
The truck weights 4.25 tons.
Check with other answers, although I'm pretty sure its correct.
Heart if helpful :D
Find the value of (-1/2)³
Answers
Answer:
-1/8
Step-by-step explanation:
(-1/2) ^3
(-1/2)(-1/2)(-1/2)
-1/8
Simplify to create an equivalent expression.
2(3y + 6) - 3(-4- y)
Choose 1 answer:
gy
5y + 24
9y - 24
9y + 24
Answers
Answer:
9y + 24
Step-by-step explanation:
2(3y + 6) - 3(-4 - y)
= 6y + 12 - 3(-4 - y)
= 6y + 12 + 12 + 3y
= 9y + 12 + 12
= 9y + 24
Answer ASAP please!
Which of the following statements is not true?
A. Pythagoras' can be used to find an unknown angle of a right-angle triangle
B. Pythagoras' theorem can be used to find an unknown side length of a right-angle triangle
C. Pythagoras' theorem can only be used on right-angle triangles
D. Trigonometry can be used to find an unknown angle of a right-angle triangle
E. Trigonometry can be used to find an unknow side length of a right-angle triangle
Answers
TRIGONOMETRY CAN BE USED TO FIND AN UNKNOWN SIDE LENGTH OF A RIGHT ANGLE TRIANGLE
Please help explanation if possible
Answers
Answer:
y= -2x +8
Step-by-step explanation:
perpendicular lines have a negative reciprocal gradient so
1/2 becomes -2/1 which is the gradient
sub in the values of x and y
2= -2 (3) +C
2= -6 + C
8=C
y=-2x +8
Answer:
y = -2x + 8
Step-by-step explanation:
for me the easiest way is simply to transform the slope and then just determine the y-intersect.
the slope of the original line is 1/2.
it is always the factor of x and represents the y/x ratio of the function (how many units is y changing when x changes a certain number of units).
a perpendicular line (90 degree angle) simply reverses x and y and the sign of the original slope.
so, the slope of the perpendicular line is -2, and the equation is
y = -2x + c
and c we get by using the point coordinates :
2 = -2×3 + c
2 = -6 + c
c = 8
so, we have
y = -2x + 8
Geometry, please answer question ASAP
Answers
Answer:
D
Step-by-step explanation:
The median goes from the vertex to the midpoint of the opposite side, so
LN = NM , that is
3x - 7 = 5 ( add 7 to both sides )
3x = 12 ( divide both sides by 3 )
x = 4
Then
KL = 2x + 3 = 2(4) + 3 = 8 + 3 = 11 → D
Find the total surface area. rectangular prism 4 A. 700 m² B. 3,040 m² C. 135 m² D. 1,308 m²
Answers
Answer:
D
Step-by-step explanation:
The opposite faces of the prism are congruent , then
SA = areas of (top/bottom + front/ back + 2 sides )
= 2(19 × 16) + 2(19 × 10) + 2(16 × 10)
= 2(304) + 2(190) + 2(160)
= 608 + 380 + 320
= 1308 m² → D
The total Surface Area is 1308 m²
What is total Surface area?The total area occupied by the surfaces of an object is called its surface area. In geometry, different 3D shapes have different surface areas which can be easily calculated using the formulas that we will be learning in this article. The surface area is classified into two categories:
Lateral surface area or Curved surface areaTotal surface areaThe total surface area of a prism = Lateral surface area of prism + area of the two bases = (2 × Base Area) + Lateral surface area = (2 × Base Area) + (Base perimeter × height).
SA = areas of (top/bottom + front/ back + 2 sides )
= 2(19 × 16) + 2(19 × 10) + 2(16 × 10)
= 2(304) + 2(190) + 2(160)
= 608 + 380 + 320
= 1308 m²
Learn more about total surface area is :
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The diameter of the Moon is 3.5 × 10^3 km.
The diameter of the Sun is 1.4×10^6 km.
Calculate the ratio of the diameter of the Moon to the diameter of the Sun.
Give your answer in the form 1 : n
Answers
Answer:
1 : 400
Step-by-step explanation:
[tex]\frac{3.5 x 10^{3} }{3.5 x 10^{3} } : \frac{1.4 x 10^{6 } }{3.5 x 10^{3} }[/tex]
1 : .4 x [tex]10^{3}[/tex]
1 : 4 x [tex]10^{2}[/tex]
1 : 400
write 3/2 4/5 8/5 in decimal notation
Answers
Answer:
hope it will help you Mark me as a brilliant
e. What order will result in a final output of 36 when the initial input is 1/7?
Answers
Answer:
5
Step-by-step explanation:
7x5=35
the remainder is 1
=5.1
the nearest number is 5
The inequalities x < -5 and -X > -5 are the same.
True
False
Answers
QUESTION-:
The inequalities x < -5 and -X > -5 are the same.
True
False
ANSWER-:
FALSE
!! HOPE ITS HELP U !!
Help me write in standard form please help!
Answers
PLEASE HELP ASAP Please?
Answers
Answer:
c
Step-by-step explanation:
First, from A to B, x=6, but y ranges from 8 to -8. From B to C, y=-8, but x ranges from 6 to -6. From C to D, x=-6, but y ranges from -8 to 8. From D to A, y=8, but x ranges from -6 to 6.
The ranges are as follows:
- x goes from -6 to 6
- y goes from -8 to 8
There are no x values less than -6, no x values greater than 6, no y values less than -8, and no y values greater than 8. x is always greater than or equal to -6 and less than or equal to 6. y is always greater than or equal to -8 and less than or equal to 8. We can write these as inequalities as follows:
x ≥ -6
x ≤ 6
y ≥ -8
y ≤ 8
The answer that is not in these 4 is c. y ≤ -8. y is never less than -8, so this is wrong
Members of a soccer team raised $1946.50 to go to a tournament. They rented a bus for $974.50 and budgeted $60.75 per player for meals. Write and solve an equation which can be used to determine pp, the number of players the team can bring to the tournament.
Answers
Answer:
16 players can be brought to the tournament. The equation is written within my step-by-step explanation.
Step-by-step explanation:
Variable p = number of players
Set up an equation:
974.50 + 60.75p = 1946.50
Isolate variable p:
60.75p = 972
Divide:
p = 16
Check your work:
974.50 + 60.75(16) = 1946.50
974.50 + 972 = 1946.50
1946.50 = 1946.50
Correct!
Answer:
Step-by-step explanation:
Put the following equation of a line into slope-intercept form, simplifying all
fractions.
15x — бу = 48
Answers
Answer:
Step-by-step explanation:
15x-6y=48
-6y=48-15x
y=-8+(15/6)x
y=(5/2)x-8
Help me pleaseeeeeeee
Answers
Answer:
The surface area is:
276cm^2
Step-by-step explanation:
10x5=50x2=100
4x5=20x2=40
10x4=40x2=80
100+40+80=220
6x2=12x4=48
2x2=4x2=8
48+8=56
220+56=276
Confirm that f and g are inverses by showing that f(g(x)) = x and g(f(x)) = x.
f(x) = 4/x
g(x) = 4/x
Answers
Answer:
Hello,
Step-by-step explanation:
[tex]f(x)=\dfrac{4}{x} \\\\g(x)=\dfrac{4}{x} \\\\\\(gof)(x)=f(g(x))=f(\dfrac{4}{x} )=\dfrac{4}{\dfrac{4}{x} } =\dfrac{4*x}{4} =x\\\\\\(fog)(x)=g(f(x))=g(\dfrac{4}{x} )=\dfrac{4}{\dfrac{4}{x} } =\dfrac{4*x}{4} =x\\[/tex]
Consider the following polynomial expression: 4x5 - 16x2 + 13x8.
Part D: what is the leading term ?
Answers
Hi there!
»»————- ★ ————-««
I believe your answer is:
[tex]13x^8[/tex]
»»————- ★ ————-««
Here’s why:
⸻⸻⸻⸻
[tex]4x^5 - 16x^2 + 13x^8[/tex]
The leading term contains the highest power of 'x'.Since 8 is greater than 5 and 2, the leading term in the give in polynomial would be [tex]13x^8[/tex].⸻⸻⸻⸻
»»————- ★ ————-««
Hope this helps you. I apologize if it’s incorrect.
5. solve for x please help
Answers
Answer:
3x -1 =27
3x=28
x=28/3
answer is option 3
[tex]\\ \sf\longmapsto 3x-1=27[/tex]
[tex]\\ \sf\longmapsto 3x=27+1[/tex]
[tex]\\ \sf\longmapsto 3x=28[/tex]
[tex]\\ \sf\longmapsto x=\dfrac{28}{3}[/tex]
Triangle QRP is congruent to triangle YXZ. What is the perimeter of triangle YXZ?
What is the perimeter of triangle YXZ?
Answers
Answer:
Perimeter of XYZ = Perimeter of QRP
Step-by-step explanation:
Since congruent then
P of XYZ = P of QRP
