Questions on Algebra: Sequences of numbers, series and how to sum them answered by real tutors!

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Question 1027538: Sn=1218
a=8
difference(b)=5
how can i find the value of n

Click here to see answer by mananth(16946) About Me 

Question 1027544: Find the 80th term in the sequence -16,-27,-38,-49
Click here to see answer by robertb(5830) About Me 

Question 1027486: Write the sigma notation for the series 800-1200+1800-2700+4050

Click here to see answer by fractalier(6550) About Me 

Question 1027966: The first three terms of a geometric sequence are: T1 ; T2 ; and T3. If T2 = T1 + 4 and T3= T2 + 9, determine the values of T1; T2 and T3
Click here to see answer by Theo(13342) About Me 

Question 1027137: Determine the first 5 susesion terms of:
Thanks for your help
bn=(-2)^(n-1)

Click here to see answer by fractalier(6550) About Me 

Question 1028162: Can you explain how to solve a problem that would ask the total amount of money a worker would receive after working at a company for 40 years and received a 3% raise every year with a starting salary of $40,000 a year?
Click here to see answer by addingup(3677) About Me 

Question 1028342: Could someone please check my work? I am supposed to label each statement as True or False, and if False, replace the words in all caps to produce a true statement.
1) A sequence is a function whose domain is A SUBSET OF THE INTEGERS. I chose False because my book states "a set of consecutive integers".
2) A sequence can be defined EITHER EXPLICITLY OR IMPLICITLY. I think this is true because a sequence can be clearly stated or implied.
3) The sum of an infinite geometric series is finite only if THE ABSOLUTE VALUE OF THE COMMON RATIO IS LESS THAN ONE. I think this is true.
I appreciate any help!

Click here to see answer by ikleyn(52788) About Me 

Question 1028399: Been trying all night to figure this out with my child....can't seem to find a pattern
101,316,192,225,283...
just need to find the next number.
if you can help please show

Click here to see answer by LinnW(1048) About Me 
Question 1028399: Been trying all night to figure this out with my child....can't seem to find a pattern
101,316,192,225,283...
just need to find the next number.
if you can help please show

Click here to see answer by Theo(13342) About Me 

Question 1028411: Could someone please check these and tell me if my answers are correct? I would appreciate it very much, I don't feel confident with my answers!
1) Find the sum of all of the 3-digit positive integers.
my answer: (999(99+1))/(2) - (99(99+1))/(2)
(999(1000))/(2) - (99(100))/(2)
(999(500)) - (99(50))
499500 - 4950 = 494550*****
2) Find the sum of every integer from 1 to 1000 that is not a perfect square.
my answer: ((1000)(1000+1))/(2)
(500)(1001)
500500*****

Click here to see answer by Alan3354(69443) About Me 

Question 1028457: How to I write the formula for a sequence that is neither geometric or explicit Example :1,8,27,64,125
Click here to see answer by Alan3354(69443) About Me 

Question 1028563: What is the sum of 12 and 99?
Click here to see answer by Fombitz(32388) About Me 

Question 1028586: Could someone please check my answers? I am supposed to write both a recursive and an explicit rule that will generate the values in the table, provided that a"subscript"o=3/2
n--------------1-----2-----3-----4------5-------6
a*sub*n------2-----3-----5-----9-----17-------33
Recursive rule= a"sub"o= 3/2, a"sub"n=a"sub"(n-1) +2 "super" n-2
Explicit rule= a"sub"n=3/2+1/2(2"super"n-1)
I hope this makes sense, I don't know how to make the subscripts on my keyboard. I appreciate any help!

Click here to see answer by Fombitz(32388) About Me 

Question 1028281: SEQUENCE IS 66 13 21 52 __ 10 20
OPTIONS 55, 56, 58, 61,62
WHY

Click here to see answer by richard1234(7193) About Me 

Question 1028709: find the twentieth term of the arithmetic sequence in which t4 = a and t12=b?
Click here to see answer by ikleyn(52788) About Me 

Question 1028744: Harper buys a car in 2007 for $20000. Each year,the car decreases in value by 18%. How much will the car be worth in 2012? round to the nearest cent.
What's the common ratio?
I got it as 0.18. Is that correct?

Click here to see answer by Theo(13342) About Me 

Question 1028777: What is the arithmetic mean an of the given terms
An-1=4,an+1=12

Click here to see answer by ikleyn(52788) About Me 

Question 1028803: We have a sequence: 11, 17, 2, 29, 31, 41, 47, ... What is the eighth number? And why?
Click here to see answer by ikleyn(52788) About Me 

Question 1028877: Find three number of G.P whose sum is 19 and product is 216
Click here to see answer by mananth(16946) About Me 
Question 1028877: Find three number of G.P whose sum is 19 and product is 216
Click here to see answer by ikleyn(52788) About Me 

Question 1029201: Write the first six terms of the sequence whose nth term is given as;
a^n = (-1)n / 2n^2 -3




Click here to see answer by stanbon(75887) About Me 

Question 1029187: Using algebraic progression:
Hanh deposited $200 into the bank on 1 January and on the first day of each of the following months. At the end of June, when the interest was calculated, he found that his account balance was $1206.30. Find the rate of simple interest paid by the bank.

Click here to see answer by stanbon(75887) About Me 

Question 1029343: How many 3-digit numbers are multiple of 21?
I can solve it by counting there is another way to solve this type of problem
Thanks

Click here to see answer by robertb(5830) About Me 
Question 1029343: How many 3-digit numbers are multiple of 21?
I can solve it by counting there is another way to solve this type of problem
Thanks

Click here to see answer by ikleyn(52788) About Me 
Question 1029343: How many 3-digit numbers are multiple of 21?
I can solve it by counting there is another way to solve this type of problem
Thanks

Click here to see answer by Edwin McCravy(20056) About Me 

Question 1029350: given the progression , m-1, 2m,3m+1, 4m+2..., determine
the common difference
the 20th term in term of m
the value of m, hence give the numerical values of the 1st three terma

Click here to see answer by Theo(13342) About Me 

Question 1029361: An object is projected vertically upwards from the ground with sufficient initial force to make it rise 105 metres in the first seconds of its flight. It travels 95 metres in the second second, 85 metres in the third seconds and so on.
a) How long does it take the object to reach its greatest height above the ground:
This is what I have so far:
I have interpreted that the greatest height above the ground must be when
Tn = 0 (or in other words at the second the object is travelling 0 metres)
I have worked this out to be 11.5 seconds, where I have used
Tn = a + (n-1) d
where n= 11.5
I have stated that although n must be an integer, in this context n refers to seconds and thus decimals are allowed. I am not sure whether this is correct.
Also the correct answer is 11 seconds, so I am a bit confused as to how this answer is obtained, as wouldn't the object would still be travelling upwards at 11 seconds and thus the greatest height above the ground wouldn't have been reached.
Thankyou for your help.


Click here to see answer by Alan3354(69443) About Me 
Question 1029361: An object is projected vertically upwards from the ground with sufficient initial force to make it rise 105 metres in the first seconds of its flight. It travels 95 metres in the second second, 85 metres in the third seconds and so on.
a) How long does it take the object to reach its greatest height above the ground:
This is what I have so far:
I have interpreted that the greatest height above the ground must be when
Tn = 0 (or in other words at the second the object is travelling 0 metres)
I have worked this out to be 11.5 seconds, where I have used
Tn = a + (n-1) d
where n= 11.5
I have stated that although n must be an integer, in this context n refers to seconds and thus decimals are allowed. I am not sure whether this is correct.
Also the correct answer is 11 seconds, so I am a bit confused as to how this answer is obtained, as wouldn't the object would still be travelling upwards at 11 seconds and thus the greatest height above the ground wouldn't have been reached.
Thankyou for your help.


Click here to see answer by ankor@dixie-net.com(22740) About Me 
Question 1029361: An object is projected vertically upwards from the ground with sufficient initial force to make it rise 105 metres in the first seconds of its flight. It travels 95 metres in the second second, 85 metres in the third seconds and so on.
a) How long does it take the object to reach its greatest height above the ground:
This is what I have so far:
I have interpreted that the greatest height above the ground must be when
Tn = 0 (or in other words at the second the object is travelling 0 metres)
I have worked this out to be 11.5 seconds, where I have used
Tn = a + (n-1) d
where n= 11.5
I have stated that although n must be an integer, in this context n refers to seconds and thus decimals are allowed. I am not sure whether this is correct.
Also the correct answer is 11 seconds, so I am a bit confused as to how this answer is obtained, as wouldn't the object would still be travelling upwards at 11 seconds and thus the greatest height above the ground wouldn't have been reached.
Thankyou for your help.


Click here to see answer by rothauserc(4718) About Me 

Question 1029596: What is the similarity between numbers 85 ,17,19,4 and2

Click here to see answer by Fombitz(32388) About Me 

Question 1029534: 5/x , 5/x^2, 5/x^3 determine the next three numbers
Click here to see answer by Fombitz(32388) About Me 

Question 1029614: Any help with this one will be appreciated!
What is the coefficient of x^{46} in the expansion of(2x-1)^{100}?

Click here to see answer by rothauserc(4718) About Me 

Question 1030264: Re-Type the is Third Number among Following List
9402, 532398, 490749

Re-Type the Second Number among Following List
83307, 284674, 660802

Click here to see answer by ikleyn(52788) About Me 

Question 1030380: The first term of G.P is x and the third term is y. Find an expression for the common ratio in terms of x and y

Click here to see answer by robertb(5830) About Me 

Question 1030376: Tweve iron poles are to be used for pillars and the length of the poles for an arithmetic progression (AP). If the third pole is 4m and the seventh pole is 10m. Find the length of the poles inorder of AP and cost of all the poles if a meter cost $45.

Click here to see answer by ikleyn(52788) About Me 

Question 1030513: The sum of three integers is
397. The sum of the first and second integers exceeds the third by
35. The third integer is
5 less than the first. Find the three integers.

Click here to see answer by ankor@dixie-net.com(22740) About Me 
Question 1030513: The sum of three integers is
397. The sum of the first and second integers exceeds the third by
35. The third integer is
5 less than the first. Find the three integers.

Click here to see answer by MathTherapy(10552) About Me 

Question 1030604: Susan’s odometer displays 15,951 miles, a palindrome. What is the minimum number of miles she must drive before it displays another palindrome?
Click here to see answer by josmiceli(19441) About Me 

Question 1030643: the first term of an arithmetic progression is 12 and the last term is 40 if the sum of the terms is 196.find the number of terms and common difference
Click here to see answer by fractalier(6550) About Me 

Question 1030735: Jeremy has a bag of peanuts. He is going to share them so he counts them out. First he uses groups of 2, then groups of 3, 5 and 8, but each time there is 1 peanut left. How many are in the bag? Is there more than one answer?
Please give me some ideas to solve this problem. Thanks !

Click here to see answer by mananth(16946) About Me 

Question 1030772: Hi. this lesson is really confusing me and I need help with it. These questions are confusing me. Please help me solve these problems.
For questions 3-5, find the first 4 terms and the 8th term of the recursively-defined sequence.
3. b1 = 2 and bk+1 = 3bk, for k>0

4. v1 = 0.75 and vn = (-2)vk-1 for n>1

5. c1 = 2, c2 = -1, and ck+2 = ck + ck+1 for k>0

6. Identify the sequence {-2, 2, -2, 2 ...} as arithmetic or geometric. Then find the common difference or ratio as appropriate.

7. Identify the sequence {-5, -2, 1, 4 ...} as arithmetic or geometric. Then find the common difference or ratio as appropriate.

8. The third and sixth terms of a geometric sequence are -75 and -9375 respectively. Find the first term, the common ratio, and an explicit rule for the nth term.

Click here to see answer by ikleyn(52788) About Me 

Question 1030673: Find the 15 th term in the sequence 0, 3, 8, 15, 24, 35, .....
any formula to solve this?

Click here to see answer by robertb(5830) About Me 

Question 1030180: Find sum to n terms of:
(2/5)-(6/5^2)+(10/5^3)-(14/5^4).......

Click here to see answer by Edwin McCravy(20056) About Me 

Question 1031460: First 5 terms of sequence:
An= 2n-3

Click here to see answer by fractalier(6550) About Me 
Question 1031460: First 5 terms of sequence:
An= 2n-3

Click here to see answer by Edwin McCravy(20056) About Me 

Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510, 3511..3555, 3556..3600, 3601..3645, 3646..3690, 3691..3735, 3736..3780, 3781..3825, 3826..3870, 3871..3915, 3916..3960, 3961..4005, 4006..4050, 4051..4095, 4096..4140, 4141..4185, 4186..4230, 4231..4275, 4276..4320, 4321..4365, 4366..4410, 4411..4455, 4456..4500, 4501..4545, 4546..4590, 4591..4635, 4636..4680, 4681..4725, 4726..4770, 4771..4815, 4816..4860, 4861..4905, 4906..4950, 4951..4995, 4996..5040, 5041..5085, 5086..5130, 5131..5175, 5176..5220, 5221..5265, 5266..5310, 5311..5355, 5356..5400, 5401..5445, 5446..5490, 5491..5535, 5536..5580, 5581..5625, 5626..5670, 5671..5715, 5716..5760, 5761..5805, 5806..5850, 5851..5895, 5896..5940, 5941..5985, 5986..6030, 6031..6075, 6076..6120, 6121..6165, 6166..6210, 6211..6255, 6256..6300, 6301..6345, 6346..6390, 6391..6435, 6436..6480, 6481..6525, 6526..6570, 6571..6615, 6616..6660, 6661..6705, 6706..6750, 6751..6795, 6796..6840, 6841..6885, 6886..6930, 6931..6975, 6976..7020, 7021..7065, 7066..7110, 7111..7155, 7156..7200, 7201..7245, 7246..7290, 7291..7335, 7336..7380, 7381..7425, 7426..7470, 7471..7515, 7516..7560, 7561..7605, 7606..7650, 7651..7695, 7696..7740, 7741..7785, 7786..7830, 7831..7875, 7876..7920, 7921..7965, 7966..8010, 8011..8055, 8056..8100, 8101..8145, 8146..8190, 8191..8235, 8236..8280, 8281..8325, 8326..8370, 8371..8415, 8416..8460, 8461..8505, 8506..8550, 8551..8595, 8596..8640, 8641..8685, 8686..8730, 8731..8775, 8776..8820, 8821..8865, 8866..8910, 8911..8955, 8956..9000, 9001..9045, 9046..9090, 9091..9135, 9136..9180, 9181..9225, 9226..9270, 9271..9315, 9316..9360, 9361..9405, 9406..9450, 9451..9495, 9496..9540, 9541..9585, 9586..9630, 9631..9675, 9676..9720, 9721..9765, 9766..9810, 9811..9855, 9856..9900, 9901..9945, 9946..9990, 9991..10035, 10036..10080, 10081..10125, 10126..10170, 10171..10215, 10216..10260, 10261..10305, 10306..10350, 10351..10395, 10396..10440, 10441..10485, 10486..10530, 10531..10575, 10576..10620, 10621..10665, 10666..10710, 10711..10755, 10756..10800, 10801..10845, 10846..10890, 10891..10935, 10936..10980, 10981..11025, 11026..11070, 11071..11115, 11116..11160, 11161..11205, 11206..11250, 11251..11295, 11296..11340, 11341..11385, 11386..11430, 11431..11475, 11476..11520, 11521..11565, 11566..11610, 11611..11655, 11656..11700, 11701..11745, 11746..11790