find the nth term of the sequence 7,25,51,85,127
Let a (n) denote the n-th term of the given sequence.
Check the forward differences, and denote the n-th difference by b (n). That is,
b (n) = a (n + 1) - a (n)
These so-called first differences are
b (1) = a (2) - a (1) = 25 - 7 = 18
b (2) = a (3) - a (2) = 51 - 25 = 26
b (3) = a (4) - a (3) = 85 - 51 = 34
b (4) = a (5) - a (4) = 127 - 85 = 42
Now consider this sequence of differences,
18, 26, 34, 42, …
and notice that the difference between consecutive terms in this sequence b is 8:
26 - 18 = 8
34 - 26 = 8
42 - 34 = 8
and so on. This means b is an arithmetic sequence, and in particular follows the rule
b (n) = 18 + 8 (n - 1) = 8n + 10
for n ≥ 1.
So we have
a (n + 1) - a (n) = 8n + 10
or, replacing n + 1 with n,
a (n) = a (n - 1) + 8 (n - 1) + 10
a (n) = a (n - 1) + 8n + 2
We can solve for a (n) by iteratively substituting:
a (n) = [a (n - 2) + 8 (n - 1) + 2] + 8n + 2
a (n) = a (n - 2) + 8 (n + (n - 1)) + 2×2
a (n) = [a (n - 3) + 8 (n - 2) + 2] + 8 (n + (n - 1)) + 2×2
a (n) = a (n - 3) + 8 (n + (n - 1) + (n - 2)) + 3×2
and so on. The pattern should be clear; we end up with
a (n) = a (1) + 8 (n + (n - 1) + … + 3 + 2) + (n - 1)×2
The middle group is the sum,
[tex]\displaystyle 8\sum_{k=2}^nk=8\sum_{k=1}^nk-8=\frac{8n(n+1)}2-8=4n^2+4n-8[/tex]
so that
a (n) = a (1) + (4n ² + 4n - 8) + 2 (n - 1)
a (n) = 4n ² + 6n - 3
The value V (in dollars) of a milling machine depends on the number of hours x it is operated as
given by the formula V = 750,000 - 120x. After one year, the value of the milling machine is
between $450,000 and $480,000.
Which range for the hours the machine is operated does this correspond to?
Basically, you have to understand the logic of a function.
V = 750,000 - 120xIf I plug in a value into V that represents the value of a milling machine, if I simplify the equation, I will be able to find x, the corresponding time to the value of the milling machine.
Knowing this logic, we can plug in $450,000 and $480,000, and then we will have two x-values. Then we can just find the range of the x-values to find our answer! :)
Let's go.
V = 750,000 - 120x
Plugged in 450,000 for V so now we can simplify the equation and find out what is the corresponding x-value for this value at this certain time.
450,000 = 750,000 - 120x
-450,000 -450,000
0 = 750,000 - 120x
+120x on both sides to isolate x
120x = 300,000
x = 2500
So, our first x-value in the range is 6250 hours. Now, let's plug in the larger value to find out the other x-value in the range.
V = 750,000 - 120x
480,000 = 750,000 - 120x
-480,000 -480,000
0 = 270,000 - 120x
Add 120x on both sides to isolate x
120x = 270,000
x = 2250
So, we found 2250 and 2500. So, the range of hours it corresponds to is 2250-2500.
Mrs. Galicia is creating a bunny farm. The farm starts with 300 bunnies and is growing at a rate of 15.25% per month. How many months will it take for the farm to double in size? *must solve using log/ln method* * DO NOT round/estimate during calculation steps* * Round your final answer, t, to 4-decimal places*
6.55 months? i dont know for sure but i tried
Case cost $3.82 , unit cost $0.32,paper cost ,$0.03, condiment cost $0.02 what is the item total cost?
Answer:
item total cost: 4.19
A model of the Eiffel Tower
uses a scale of 1 cm - 4 meters.
If the model is 75 a centimeters
tall, what is the actual height
of the Eiffel Tower?
Answer:
The correct answer is A. The actual height of the Eiffel Tower is 301 meters.
Step-by-step explanation:
Given that a model of the Eiffel Tower uses a scale of 1 cm - 4 meters, if the model is 75 1/4 a centimeters tall, to determine what is the actual height of the Eiffel Tower the following calculation must be performed:
1 = 4
1/4 = 0.25
75.25 x 4 = X
301 = X
Therefore, the actual height of the Eiffel Tower is 301 meters.
what is the conjugation ending of er verb
Answer:
je -parle
tu - parles
il/elle/on - parle
nous - parlons
vous - parlez
ils/elles - parlent
Answer:
Verbs with infinitives ending in -er form a second group of regular verbs in Spanish, often called second conjugation verbs.
Step-by-step explanation:
To conjugate these verbs in the present tense, drop the -er from the infinitive and add the second conjugation present tense endings: -o, -es, -e, -emos, -en.
Kelko wrapped 20 gifts. Keiko wrapped 4 times as many gifts as Henry. Let be the number of gifts that Henry wrapped.
(a) Write an equation that relates the number of gifts that they wrapped.
Use 4, 20, and n.
(b) Find n.
2
Answer:
20 = 4n
n = 5
Step-by-step explanation:
Given that :
Number of gifts Keiko wrapped = 20
Let number of gifts wrapped by Henry = n
Keiko wrapped 4 times as many gifts as Henry
Hence,
20 = 4n
The equation that relates the number of gifts wrapped is :
20 = 4n
To obtain n ;
Divide both sides by 4 to isolate n
20/ 4 = 4n / 4
5 = n
Hence,
n = 5
the original piece of a book is $25. the book is on sale for 30% off. what percent are we paying? what is the price you will pay for the book
show work please and thank you :)
Answer:
$17.50
Step-by-step explanation:
multiply 25 and 30, the divide the answer by 100, the deduct that result from the original price
Help please?
I’m struggling on this the teacher didn’t teach us this
Answer:
58°
Step-by-step explanation:
A flat angle equals 180°, so we can simply subtract the given angle from the total, 180.
180 - 122 = 58
So, ∠CDE = 58°.
Good luck n.n
Answer:
58°
Step-by-step explanation:
∠AEC =∠AED+∠CED
So,
∠AEC=180°
∠AED=122°
∠CED=?
∠AEC =∠AED+∠CED
180°=122°+∠CED
∠CED=180°-122°
∠CED=58°
Janice has $2.46 worth of coins in her pocket. The coins are of four different denominations, and she has the same number of each denomination. What are the four denominations, and how many of each does she have?
The number of the same coin that she has will be 6.
What is Algebra?The analysis of mathematical representations is algebra, and the handling of those symbols is logic.
Janice has $2.46 worth of coins in her pocket. The coins are of four different denominations, and she has the same number for each denomination.
If there are any pennies, nickels, dimes, or quarters on Janice. Trial and error led me to the following conclusions:
1 of each coin: 0.01 + 0.05 + 0.10 + 0.25 = 0.41
2 of each coin: 0.02 + 0.10 + 0.20 + 0.50 = 0.82
3 of each coin: 0.03 + 0.15 + 0.30 + 0.75 = 1.23
4 of each coin: 0.04 + 0.20 + 0.40 + 1.00 = 1.64
5 of each coin: 0.05 + 0.25 + 0.50 + 1.25 = 2.05
6 of each coin: 0.06 + 0.30 + 0.60 + 1.50 = 2.46
Based upon these results, Janice has 6 of each coin.
Let x be the number of coins. Then we can set up the equation will be
0.01x + 0.05x + 0.10x + 0.25x = 2.46
0.41x = 2.46
x = 6
The number of the same coin that she has will be 6.
More about the Algebra link is given below.
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A machine produces metal pieces that are cylindrical in shape. A sample of pieces is taken, and the diameters are found to be 1.01, .97, 1.03, 1.04, .99, .98, .99, 1.01, and 1.03 centimeters. Find a 99% confidence interval for the mean diameter of pieces from this machine, assuming an approximate normal distribution. Interpret the interval carefully in the context of the problem
please help!!!!! What is the surface area of the right cone below?
slanted hight: 15
radius: 8
A. 1847 units2
B. 304 units2
C. 2487 units2
D. 4967 units
Answer:
Total surface area of cone = 578.28 unit²
Step-by-step explanation:
Given:
Slanted Hight of cone = 15 unit
Radius of cone = 8 units
Find:
Total surface area of cone
Computation:
Total surface area of cone = πr[l + r]
Total surface area of cone = (22/7)(8)[15 + 8]
Total surface area of cone = (22/7)(8)[23]
Total surface area of cone = (22/7)(184)
Total surface area of cone = 4,048 / 7
Total surface area of cone = 578.28 unit²
Arlie is on an airplane that has traveled 420 miles in 3/4 of an hour. At this rate, how far will the airplane travel in the next 1/2 hour?
How did waterways provide Detroit with such a vital military position?
Answer:
Your source water comes from the Detroit River, situated within the Lake St. Clair, Clinton River, Detroit River, Rouge River and Ecorse River watersheds in the U.S., and parts of the Thames River, Little River, Turkey Creek and Sydenham watersheds in Canada.
Step-by-step explanation:
please mark this answer as brainliest
Which of these describes two thirds?
Answer:
2/3
two thirds
0.666666666
Step-by-step explanation:
please mark this answer as brainliest
Essentials of University Mathematics
Example 3.
Find the length of the vector PQ from the point P(3.-5. 2) to the
point QC-5.4.9)
Find a unit vector with the direction of PQ
Answer:
The length of the vector is of [tex]\sqrt{194}[/tex]
The unit vector with the direction of PQ is [tex](\frac{8}{\sqrt{194}}, \frac{9}{\sqrt{194}}, \frac{7}{\sqrt{194}}[/tex]
Step-by-step explanation:
Vector from point P(3,-5,2) to Q(-5,4,9)
The vector is:
[tex]PQ = Q - P = (-5-3, 4-(-5), 9-2) = (8,9,7)[/tex]
The length is:
[tex]\sqrt{8^2+9^2+7^2} = \sqrt{194}[/tex]
The length of the vector is of [tex]\sqrt{194}[/tex]
Find a unit vector with the direction of PQ
We divide each component of vector PQ by its length. So
[tex](\frac{8}{\sqrt{194}}, \frac{9}{\sqrt{194}}, \frac{7}{\sqrt{194}}[/tex]
The unit vector with the direction of PQ is [tex](\frac{8}{\sqrt{194}}, \frac{9}{\sqrt{194}}, \frac{7}{\sqrt{194}}[/tex]
WILL MARK BRAINLIEST!!! PLEASE ANSWER!!! WRONG ANSWERS JUST FOR POINTS WILL BE REPORTED!!!!!!!!!!!!!!
Answer:
916.1 cm^3
Step-by-step explanation:
1) find the radius of the cylinder:
radius = dimater / 2 = 7,3 / 2 = 3.65 cm
2) find the base area of the cylinder:
base area = radius^2 x 3.14 = 3.65^2 x 3.14 = 41.83265 cm^2
3) find the height of the cylinder:
height = 7.3 x 3 = 21.9 cm
4) find the volume
V = base area x height = 41.83265 x 21.9 = 916.135035 cm^3
5) round to nearest tenth:
916. 1 cm^3
John went to his baseball game. His mom dropped him off at 4:40 pm and he left his game at 7:50 pm. How long was John at his game?
Answer:
I got 3 hours and 10 minutes
Step-by-step explanation:
If you continuously add numbers in decimal form you will find the answer also.
But also another way in order to find a time answer you could also subtract
7.50-4.40= 3.10
or just 3.1 in this case.
But in a time frame always add the 0 to it.
So 3 hours and 10 minutes!
I think so indeed.
How much simple interest is earned on $4,000 in 3 1/2 years at an interest rate of 5.2%?
Answer:
$728
Step-by-step explanation:
The formula for simple interest is I = PRT, where I = interest earned/paid, P = principal amount deposited or borrowed, R = rate of interest as a decimal, and T = time in years.
I = PRT
I = (4000)(0.052)(3.5)
I = 728
Simple Interest earned on $4000 in three and half year with 5.2% interest rate is $ 728.
What is Simple Interest?Simple interest is a method to calculate the amount of interest charged on a sum at a given rate and for a given period of time.
Here, Principal = $ 4000
Time = [tex]3\frac{1}{2}[/tex] years = 7/2 years = 3.5 years
Rate = 5.2 % = 0.052
Now, SI = P.R.T/100
SI = 4000 X 3.5 X 5.2 / 100
SI = $ 728
Thus, Simple Interest earned on $4000 in three and half year with 5.2% interest rate is $ 728.
Learn more about Simple Interest from:
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If there were five times as many children as adults at the picnic and there were at least 120 people at the picnic, how many adults and children were at the picnic?
Answer:
20 adults
100 Children
Step-by-step explanation:
Answer: 20 adults and 100 children
Step-by-step explanation:
a = adults, c = children
120 = a + c
c = 5a
120 = a + 5a
120 = 6a
20 = a
20 times 5 is 100 so 100 children
Suppose a student typically spends 5/2 hours each week doing research on the Internet. How much research time does a student spend each device in 1 week?
Answer:
Step-by-step explanation:
5/2 hours = 2 1/2 hours
2 1/2 hours = 120 minutes + 30 minutes = 150 minutes.
I don't know if he has more than 1 device or not. But if he does, then this time is the base and you just multiply by 2 1/2 for each device.
Answer:
Solution given:
a student typically spends 5/2 hours each week
research time does a student spend each device in 1 week=5/2=2hours and 30min=150minutes
What is the area?
4.6 yd
7.7 yd
Answer:
A = 35.42 yd²
Step-by-step explanation:
We need to find the area if the dimensions are given as 4.6 yd and 7.7 yd.
The area of a rectangle shaped figure is given by :
A = lb
Where
l is length and b is the breadth
So, put all the values,
A = (4.6)(7.7)
= 35.42 yd²
So, the area of the figure is equal to 35.42 yd².
What is the area=???
Answer:
5x^2 + 2
Step-by-step explanation:
pretty sure
Answer:
6.25
Step-by-step explanation:
x+2=5x
2= -x+5x
2=4x
2/4=4x/4
1/2=x
Plug into formla of rectangel: L*W
L= 5(0.5)= 2.5
W= 0.5+2 = 2.5
L*W= 2.5*2.5 = 6.25
You used 15.6 kWh to recharge an EV at a cost of 11.6 cents per kWh. How
much did you spend to recharge the car?
$180.96
$18.00
$1.36
$1.81
Answer:
1.81
Step-by-step explanation:
the reason is because many may think by using a calculator, and make a mistake by putting 15.6 x 11.6, and think "Oh its 180.96" but they forget that they are multiplying cents, but with money you round the nearest decimal to a cent, so they get 1.81
15.6 x 11.6 = 180.96
flip it and jump the 1 a single spot to the left. (1 80.96)
Now jump the decimal between the 1, and the 8. (1.8096)
Now round the thousandth and ten thousandth to remove the zero and make it one. (1.8096= 1.81)
And that's how you get 1.81
if i'm wrong I need to go back to 5th grade and learn my money and decimals semester.
terest formula to compute the total amount accumulated and
$5000 for 3 years at 1.7% compounded monthly
The total amount accumulated after 3 years is $ 5,261.42
(Round to the nearest cent as needed.)
The amount of interest earned is $
(Round to the nearest cent as needed.)
Answer:
Interest = $261.42
Step-by-step explanation:
amount of interest earned is $
(Round to the nearest cent as needed.)
Amount = Principal + Interest
Amount - Principal = Interest
$ 5,261.42 - $5000 = Interest = $261.42
Referring to the figure, find the volume of the solid shown. Round to the nearest whole number. Will mark brainliest...
Answer:
648
Step-by-step explanation:
FInd volume of bottom half (9x6x12)
find voume of pyramid 1/3Bh 1/3(11)(54)
Two mechanics worked on a car. The first mechanic worked for 15 hours, and the second mechanic worked for 5 hours. Together they charged a total of $1725.
What was the rate charged per hour by each mechanic if the sum of the two rates was $195 per hour?
Note that the ALEKS graphing calculator can be used to make computations easier.
х
5
?
First mechanic: $ [per hour
Second mechanic: $ per hour
Answer:
75
120
Step-by-step explanation:
Let the first mechanic's hourly rate = x
Let the second mechanic's hourly rate = y
x + y = 195
15x + 5y = 1725 Divide this equation by 5
3x + y = 345 Write the first equation below this one. Subtract
x + y = 195
2x = 150 Divide by 2
x = 150/2
x = 75
====================
x + y = 195
75 + y = 195
y = 195 - 75
y = 120
10 people ate pie and 1 person ate cake. How many more people at the pie than the cake?
Answer:
9
Step-by-step explanation:
10 subtract 1 is 9.
Given:
10 people ate pie
1 person ate cake
No of people who ate the pie than the cake
10-1 =9
Rewrite 2+(1/b-2) = (3b/b+2) as a proportion. Which of these proportions is equivalent to the original equation?
A. (3/b-2) = (3b/b+2)
B. (2b+3/b-2) = (3b/b+2)
C. (2b-3/b-2) = (3b/b+2)
and asking 2nd part question and answer. thx
Answer:
C for the first one
1,6 for the second
Neither for the third
Step-by-step explanation: EDGE 2021
Answer:
The first Question is C
Question 2 is 1,6
Question 3 is Neither
Step-by-step explanation:
trust me I took the quiz
[tex]16 \: 3 \: by \: 4[/tex]
evaluate the answer according to the law of exponents
Answer:
16 3/4=[16×4+3]/4=67/4 is your answer