Answer:
1. W=15 L=5 or W=5 L=15.
Step-by-step explanation:
Diego made the shape on the left, and Elena made the shape on the right. Each shape uses 5 circles.
Select all the true statements.
Answer:
I think 2 and 3
Step-by-step explanation:
-5 = -2x + 27 - 3x this has to be 20 characters so ignore this lollllll
Answer:
6 2/5=x
Step-by-step explanation:
write an equivalent fraction of 7/8 5/12 4/18
Answer:
Step-by-step explanation:
7/8 is 63/72
5/12 is 25/60
4/18 is 8/36
I need help asap for these answers
The expression for the sum to 'n' terms of some Arithmetic Sequence are given beliw. Find the 'nth' term of each
i)n^2+2n
ii) n^2- 2n
Arithmetic Sequence
Find:'nth' term of each
i)n^2+2n
ii) n^2- 2n
Solution:1) Sum of first n terms = n² + 2n
We know that,
Sum of first n terms = n/2 * [ a + l ]
Where,
a is first term
l is nth or last term.
Substitute n = 1 to find the sum of first 1 terms i.e., first term (a) of the AP.
→ S₁ = a = (1)² + 2(1)
→ a = 1 + 2
→ a = 3
Hence,
→ n/2 * [ a + l ] = n² + 2n
→ a + l = n(n + 2) * 2/n
→ a + l = 2n + 4
→ l = 2n + 4 - a
→ l = 2n + 4 - 3
→ l = 2n + 1
Hence, the nth term is 2n + 1.
2)S(n) = n² - 2n
→ S₁ = a = (1)² - 2(1)
→ a = - 1
Hence,
→ n/2 * [ - 1 + l ] = n² - 2n
→ l - 1 = n(n - 2) * 2/n
→ l - 1 = 2n - 4
→ l = 2n - 4 + 1
→ l = 2n - 3
Hence, the nth term is 2n - 3.
I hope it will help you.
Regards.
Step-by-step explanation:
Series
The series of a sequence is the sum of the sequence to a certain number of terms. It is often written as Sn. So if the sequence is 2, 4, 6, 8, 10, ... , the sum to 3 terms = S3 = 2 + 4 + 6 = 12.
The Sigma Notation
The Greek capital sigma, written S, is usually used to represent the sum of a sequence. This is best explained using an example:
This means replace the r in the expression by 1 and write down what you get. Then replace r by 2 and write down what you get. Keep doing this until you get to 4, since this is the number above the S. Now add up all of the term that you have written down.
This sum is therefore equal to 3×1 + 3×2 + 3×3 + 3×4 = 3 + 6 + 9 + 12 = 30.
3
S 3r + 2
r = 1
This is equal to:
(3×1 + 2) + (3×2 + 2) + (3×3 + 2) = 24 .
The General Case
n
S Ur
r = 1
This is the general case. For the sequence Ur, this means the sum of the terms obtained by substituting in 1, 2, 3,... up to and including n in turn for r in Ur. In the above example, Ur = 3r + 2 and n = 3.
Arithmetic Progressions
An arithmetic progression is a sequence where each term is a certain number larger than the previous term. The terms in the sequence are said to increase by a common difference, d.
For example: 3, 5, 7, 9, 11, is an arithmetic progression where d = 2. The nth term of this sequence is 2n + 1 .
In general, the nth term of an arithmetic progression, with first term a and common difference d, is: a + (n - 1)d . So for the sequence 3, 5, 7, 9, ... Un = 3 + 2(n - 1) = 2n + 1, which we already knew.
The sum to n terms of an arithmetic progression
This is given by:
Sn = ½ n [ 2a + (n - 1)d ]
You may need to be able to prove this formula. It is derived as follows:
The sum to n terms is given by:
Sn = a + (a + d) + (a + 2d) + … + (a + (n – 1)d) (1)
If we write this out backwards, we get:
Sn = (a + (n – 1)d) + (a + (n – 2)d) + … + a (2)
Now let’s add (1) and (2):
2Sn = [2a + (n – 1)d] + [2a + (n – 1)d] + … + [2a + (n – 1)d]
So Sn = ½ n [2a + (n – 1)d]
Example
Sum the first 20 terms of the sequence: 1, 3, 5, 7, 9, ... (i.e. the first 20 odd numbers).
S20 = ½ (20) [ 2 × 1 + (20 - 1)×2 ]
= 10[ 2 + 19 × 2]
= 10[ 40 ]
= 400
Geometric Progressions
A geometric progression is a sequence where each term is r times larger than the previous term. r is known as the common ratio of the sequence. The nth term of a geometric progression, where a is the first term and r is the common ratio, is:
arn-1
For example, in the following geometric progression, the first term is 1, and the common ratio is 2:
1, 2, 4, 8, 16, ...
The nth term is therefore 2n-1
The sum of a geometric progression
The sum of the first n terms of a geometric progression is:
a(1 - rn )
1 – r
We can prove this as follows:
Sn = a + ar + ar2 + … + arn-1 (1)
Multiplying by r:
rSn = ar + ar2 + … + arn (2)
(1) – (2) gives us:
Sn(1 – r) = a – arn (since all the other terms cancel)
And so we get the formula above if we divide through by 1 – r .
Example
What is the sum of the first 5 terms of the following geometric progression: 2, 4, 8, 16, 32 ?
S5 = 2( 1 - 25)
1 - 2
= 2( 1 - 32)
-1
= 62
The sum to infinity of a geometric progression
In geometric progressions where |r| < 1 (in other words where r is less than 1 and greater than –1), the sum of the sequence as n tends to infinity approaches a value. In other words, if you keep adding together the terms of the sequence forever, you will get a finite value. This value is equal to:
a
1 – r
Example
Find the sum to infinity of the following sequence:
1 , 1 , 1 ,
1
,
1
,
1
, ...
2 4 8 16 32 64
Here, a = 1/2 and r = 1/2
Therefore, the sum to infinity is 0.5/0.5 = 1 .
So every time you add another term to the above sequence, the result gets closer and closer to 1.
Harder Example
The first, second and fifth terms of an arithmetic progression are the first three terms of a geometric progression. The third term of the arithmetic progression is 5. Find the 2 possible values for the fourth term of the geometric progression.
The first term of the arithmetic progression is: a
The second term is: a + d
The fifth term is: a + 4d
So the first three terms of the geometric progression are a, a + d and a + 4d .
In a geometric progression, there is a common ratio. So the ratio of the second term to the first term is equal to the ratio of the third term to the second term. So:
a + d = a + 4d
a a + d
(a + d)(a + d) = a(a + 4d)
a² + 2ad + d² = a² + 4ad
d² - 2ad = 0
d(d - 2a) = 0
therefore d = 0 or d = 2a
The common ratio of the geometric progression, r, is equal to (a + d)/a
Therefore, if d = 0, r = 1
If d = 2a, r = 3a/a = 3
So the common ratio of the geometric progression is either 1 or 3 .
:( CAN SOMEONE PLEASE HELP ME
Answer:
I think that Nick is correct because you are going to have to make your answer positive and when you do the two fractions -4/9 + -6/9 are going to be 6/9 + 4/9 and there is already a addition sign in the last problem we are just going to keep it there. And when we add we get 10/9 or 1 1/9
If i get it wrong please don't hate im just in 7 grade ok :(
Answer:
Solution given:
Gobriella is correct.
Nick change - to + in second line.
According to a Wired magazine article, of e-mails that are received are tracked using software that can tell the e-mail sender when, where, and on what type of device the e-mail was opened (Wired magazine website). Suppose we randomly select received e-mails.
a.The expected number of emails is 12
b. The variance and the standard deviation is 7.200 and 2.683
Calculation of expected number of emails, variance and standard deviation:
Given that
P = 0.40 and n = 30
a)
The expected value of received e-mails is
= n × p
= 30 × 0.4
= 12
b)
The variance of emails received is
= n × p × (1 - p)
= 30 × 0.4 × 0.6
= 7.200
Now
The standard deviation of emails received is
= sqrt(variance)
= 2.683
We simply applied the above formula
Learn more about variance here: https://brainly.com/question/24138432
−2(−x+4) − 3x+2= −5 what is x?
Answer:
−2(−x+4) − 3x+2= −5 what is x? Well i might be wrong but i think its 2x
Step-by-step explanation:
PEMDAS USE THAT METHOD
Answer: x=-1
Step-by-step explanation:
I need help this is my last page
Answer:
The number: 85 factors: 17, 1
Step-by-step explanation:
136-51=85
85 and 51
Common factors of 85 and 51
17,1
7. When rice is prepared, the amount of rice varies directly as the amount of water
required. If 2 cups of rice requires 4.5 cups of water, what is the total number of cups
of water needed to prepare 5 cups of rice?
Answer:
11.25
Step-by-step explanation:
Multiply 4.5 by the reciprocal of 2/5, which is 5/2. You will then get 11.25. Hope this helped :)
Total number of cups of water needed to prepare 5 cups of rice are 11.25.
What is mean by Ratio?
A ratio indicates how many times one number contain in another number. The ratio of two number is written as x : y, which is equivalent to x/y.
Where, x and y are individual amount of two quantities.
And, Total quantity gives after combine as x + y.
Given that;
When rice is prepared, the amount of rice varies directly as the amount of water required.
And, 2 cups of rice requires 4.5 cups of water.
Now,
Since, 2 cups of rice requires 4.5 cups of water.
Hence, For 1 cup of rice, number of cups of water = 4.5 / 2
= 2.25
So, For 5 cups of rice, number of cups of water = 5 x 2.25
= 11.25
Thus, Total number of cups of water needed to prepare 5 cups of rice are 11.25.
Learn more about the ratio visit:
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Guys Please HELP ME
If you give me answer quickly, I'll give you brainliest. Please help me (20 points)
Questions
1. Find the density of a cylinder with a height of 4mm, a radius of 4mm, and a mass of 250g
2. Find the density of a sphere with radius of 2m and a mass of 2kg
Answer:
Step-by-step explanation:
1st one is 62.5 kilogramic meter
2nd one is 1 kilo kilogram/cubic meter
Step-by-step explanation:
1)First calculate the volume
v=Pir²h
v=3.15×4²×4
v=201mm³
p=m/v
p=0.250/0.201
p=1.24Kg/m³
2)v=3/4pi r³
v=3/4×3.14×2³
v=33.5m³
p=m/v
p=2/33.5
p=0.0597kg/m³
Consider the graph of f(x)=x^3-3x^2+2x-6 below
1) what is the real solution of f(x) based on the graph? Verify algebraically that your answer is a zero f(x).
2) factor f(x)
3) find all complex zeros of f(x)
4) write as a product of three linear factors
Answer:
Step-by-step explanation:
Two friends operate a trucking company that delivers Goods across three states they lose $24.50 each time a customer chooses to make a delivery with a competitor? Which expression shows the amount that the trucking company makes if P people use a competitor for delivery and the company makes $3,125 before the competition is considered
Answer:
3,125; 24.5p
Step-by-step explanation:
Answer:
3125-24.5p and 2,978
Step-by-step explanation:
What is the value of g?
25(g−7)=3
Answer: G=7.12
Step-by-step explanation: 25g-175=3 add 175 to both side which makes the equation 25g=178 and divide 178 by 25 which gives you 7.12
Answer:
g=178/25
Step-by-step explanation:
Step 1: 25(g-7)/25=3/25
Step2: g-7=3/25
Step 3: g-7+7=3/25 + 7
Answer: g=178/25
Decimal form would be g=7.12
A hot air balloon ascended at the rate of
400 feet per hour for 3 hours and 15
minutes. What was the total distance that
the balloon ascended?
Answer: the answer is 1300 hope this helps you
Step-by-step explanation:
hi I dont really understand
Answer:
Option 2
Step-by-step explanation:
The length is unknown, so it is l for now. A rectangle has 2 lengths and widths, so the values are 2w and 2l. The sum of 2w and 2l have to be greater than or equal to 776, so the answer is option 2. If you solve the inequality, the length is equal to or greater than 355
What is the solution to 4 x + 6 less-than-or-equal-to 18?
help
<3
Answer:
x is less-than-or-equal to 3
Step-by-step explanation:
4(3)+6 =18
What is the measure, in degrees, of Angle 1
Answer:
54
Step-by-step explanation:
126+54=180
what are all the factors of 21?
Answer:
1, 3, 7, 21
p-by-step explanation:
Which could be the first step of an indirect proof of the conditional below?
If x2 = 25, then 5’2= 25 and x = 5,
A. Assume x=5 is true.
B. Assume 52 = 25 is true,
C. Assume x2 + 25 is true.
D. Assume 52.25 and x + 5 are true,
Answer
Option D
Step-by-step explanation
For further help (727) 335-8234
The first step of indirect proof of the conditional below
If x2 = 25, then 5’2= 25 and x = 5 is assume 5² = 25.
Option B is the correct answer.
What is an equation?An equation is a mathematical statement that is made up of two expressions connected by an equal sign.
We have,
Conditions:
x² = 25 then 5² = 25 and x = 5
If we have to prove the above conditions indirectly, we have to prove that x² = 25 using the conditions 5² = 25 and x = 5.
So,
We have to assume,
Step 1:
5² = 25
Step 2:
x = 5
Step 3:
x² = 25
Thus,
The first step of indirect proof of the conditional below
If x2 = 25, then 5’2= 25 and x = 5 is assume 5² = 25.
Option B is the correct answer.
Learn more about equations here:
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can someone help me with this
The length of the rectangle is four times it’s width. The rectangle has an area of 1024cm2. What is the width of the rectangle
Answer:
Length = 4 times width
Area = length * width
=(4w)w
=4w²
So 4w²=1024 cm² (given)
w²=1024/4=256
w=√(256 cm²)
=16 cm (reject negative value of square-root)
Step-by-step explanation:
Hope this helps you
Crown me as brainliest:)
w is no more than -7
Answer:
w≤-7
Step-by-step explanation:
No more than means it has to be -7 or less so w is no more than -7 is w≤-7
Hope this helps!
Answer:
I agree if that's what you say it mean
Find the product (10)(-2)(-3)
Answer:
60
Step-by-step explanation:
(10)(-2)(-3) = ?
The minuses cancel out each other
10*2*3 --> 20* 3
Simplified Math
60
Sum
Luke can purchase a 10-pound item from several different stores. Which of the following is the best buy?
Answer:
What are the stores & the data?
How did Washington react to failure?
What are the slope and the y-intercept of the linear function that is represented by the table?
Х
3
4
y
1
30
2
1
2
15
1
4
13
30
NICO
3
5
Answer:
1/4
Step-by-step explanation:
If f(x)=3x+2 and g(x)=x^2-x, find the value.
g(-3)=
Answer:
hence the ans of g(-3)=12
Determine if the following is a PROPORTIONAL
relationship or NONPROPORTIONAL relationship.
y = -2x + 2
WHat is 9 to the the power of infinity timees the number of cubic inches
Answer:
...infinity cubic inches?
Step-by-step explanation: