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

Tutors Answer Your Questions about Sequences-and-series (FREE)

Question 344123: Find the sum of the indicated terms of the geometric sequence: 6, 18, 54 . . . (to 7 terms)

Click here to see answer by camerontdy(1)

Question 430945: (n+2)!/(n)!
Click here to see answer by josmiceli(19441)

Question 431449: 5th term in expansion of (2x-1)^7 ?
Click here to see answer by Gogonati(855)

Question 431483: Find the next three terms of sequence 1,2,4,7,11,16...
Click here to see answer by Gogonati(855)

Question 431805: Find the arithmetic mean an of the given terms
An-1=100, an+1=140
Click here to see answer by shree840(260)

Question 431938: Which term is the number 136 in the sequence 1, 6, 11, 16, 21?
Click here to see answer by ewatrrr(24785)

Question 431863: 1.Write in sigma notation:
0+3+8+15+24+35+48
2. Find the 10th term of the arithmetic sequence:
3/4, 13/12,17/12,..
3. Find the 6th term of the arithmetic sequence:
a-b, a, a+b,...
4. The common difference in an arithmetic sequence is 3. The 10th term is 23. Find the first term.
5. Insert 4 arithmetic means between 5 and 9.
Click here to see answer by htmentor(1343)

Question 431920: Please help me.
I am trying to find the scientific Notation of
10,453.895
and
0.4584267
Please explain to me how to write these numbers in scientific notation.
Click here to see answer by josmiceli(19441)

Question 432068: Write a variable expression to describe the rule for each sequence. Then find the hundredth term.
3,6,9,12
14,15,16,17
21,42,63,84
-10,-9,-8,-7
Thanks, Sheila
Click here to see answer by ewatrrr(24785)

Question 432730: I have to do a worksheet on sequences and i tried working problem one but i don't think im getting anywhere.
1.) 9,18,27,36
I have to find the next 3 terms.
I think its all multiplied by 3 but im not sure.

Click here to see answer by edjones(8007)

Question 432735: 2+5+8+..59 arithmetic sequence?
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Question 432735: 2+5+8+..59 arithmetic sequence?
Click here to see answer by richard1234(7193)

Question 433155: Which represents the series 1+1/3+1/9+1/27+1/81+1/243 using sigma notation? (Points : 4) D. http://takeexam.next.ecollege.com/ec/Courses/25253/CRS-K12VHS-3840876/Q7D.jpg C. http://takeexam.next.ecollege.com/ec/Courses/25253/CRS-K12VHS-3840876/Q7B.jpg B. http://takeexam.next.ecollege.com/ec/Courses/25253/CRS-K12VHS-3840876/Q7C.jpg A. http://takeexam.next.ecollege.com/ec/Courses/25253/CRS-K12VHS-3840876/Q7A.jpg
Click here to see answer by ewatrrr(24785)

Question 434295: write the next term in the sequence. then write a rule for the nth term..

-5, 10, -15, 20, ?
Click here to see answer by solver91311(24713)

Question 434561: 1) Find the fraction form of 8.25 recurring Please help
I keep getting 817/99 but upon checking its not quite right
2) Find the first four terms of the expansion(x-3)^6, this has me stumped Please help, thank you in advance
Click here to see answer by stanbon(75887)

Question 435103: Circumscribed and Inscribed rectangles.
Can someone please show me how to do these?
1: Use circumscribed rectangles to approximate the area under the graph for the function: f(x)=5-(1/4)x^2, for 0<=x<=3.
2: Use inscribed rectangles to approximate the area under the graph for the function f(x)=sqrt(3+x), for -3<=x<=0.
Thank you
Click here to see answer by stanbon(75887)

Question 435298: what is the first term in the sequence for which d=1/3 a7=10 2/3
Click here to see answer by ewatrrr(24785)

Question 435617: The sum of the first n terms of an arithmetic squence is given by the formula; Sn= n/2 (3n-13)=
i) Find the sum of the first two terms
ii) Find the sum of the first three terms
iii) Find the first three terms of the sequence
iv) How many terms of this sequence are required to give a sum of 85?
Click here to see answer by edjones(8007)

Question 435830: find the hundreth term 7,12,17 what is the 100th term?!?!
Click here to see answer by ewatrrr(24785)

Question 436353: Determine whether each sequence could be arithmetic. If so, find the common difference and the next term.
Question 1;
46, 39, 32, 25, 18, ...
Click here to see answer by rwm(914)

Question 436653: this problem is out of my algebra book on Geometric sequences. It is asking for the 1st (which i think is given in the formula) 4th and 8th terms. If you only do one, please do the 8th term
A(n)= -1.1x(-4)^n-1 (i am using x to mean multiply)
Isn't the given -1.1 the first term? I see that the ratio (also given) is a -4. This is giving me the most problems. I get the 4th term as 70.4 and the 8th term as 18022.4 BUT that leaves all the terms alternating in a postive, negative fashion. Didnt think you could do that. Help please.
Thank you
Click here to see answer by stanbon(75887)

Question 436711: 1. find the 7th term in 16, 8, 4,....

2. Find the sum of the first 11 terms in the sequence 4,6,9...

3. What is the sum of the first 100 even numbers
Click here to see answer by stanbon(75887)

Question 436878: Jenny sits and writes:mathsmaths...if she continues in this patter what will the 2007 letter be?
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Question 437863: what is the explicit formula to the sequence 360,180,90,45
Click here to see answer by solver91311(24713)

Question 438145: find the nth term of the sequence 5,-10,15,-20
Click here to see answer by robertb(5830)

Question 438147: express the sum using summation notation: 6^2+12^3+18^4+...+48^9
Click here to see answer by robertb(5830)

Question 438181: the following sum is a partial sum in a geometric sequence, use this fact to evaluate the sum.
3+12+...+786432
Click here to see answer by robertb(5830)

Question 438197: hi, i really need help with this. find the sum of the sequence: sigma (2k+7) k=1 and there are 16 terms (on the top of sigma)
Click here to see answer by robertb(5830)

Question 438234: can you please show me how to solve the following problem: show that the statement is true for n^2-n+2 is divisible by 2
Click here to see answer by robertb(5830)

Question 438222: hi there.
i need help with this problem: prove the sum of the first n term of a geometric sequence ...
Click here to see answer by robertb(5830)

Question 438196: Let , for x in [0,1]. Show whether or not
i) converges for each x in [0,1].
ii) converges uniformly on [0,1].
Click here to see answer by robertb(5830)

Question 438225: use the principal mathematical induction to show that the statement is true for all natural numbers n.
9+18+27+...+9n= 9n(n+1)/2
Click here to see answer by Gogonati(855)

Question 438685: Hi, I'm having a really tough time with these two questions. Any help is greatly appreciated, thank you!
1. For the sequence 15,12,9,... find the common difference and the nth term.
2. If 3x-1, 2x+2 and 2x-1 are in Arithmetic Progression, find value of x.

Click here to see answer by richard1234(7193)

Question 438696: Summation: i=1 to 1000 (i^(1/3))
Is this approximately equal to the integral: 1 to 1000 (x^(1/3))dx?
Click here to see answer by richard1234(7193)

Question 438686: Hello, how do I find the first term of the sequence -7,-5,-3,... which is greater than 400. I think it might be 401 but could someone check my answer? Thank you!
Click here to see answer by richard1234(7193)

Question 438761: what is the pattern in: 1,8,27,64??
Click here to see answer by robertb(5830)

Question 439116: Find the sum of n terms of the series
1+2+4+7+11+16++22+...+(nth term)
Click here to see answer by Edwin McCravy(20056)

Question 439410: The product of three consecutive terms in a geometric sequence is -1000, and their sum is 15. Find the common ratio.
Click here to see answer by robertb(5830)

Question 439530: I am having trouble with this question:
Write a formula for the general term (the nth term) of the arithmetic sequence whose second term, a base7 is 4 and whose ninth term, a base is 12.
I am thinking the formula to use is an= a1+(n-1)d
an=1(12-1)4
Is this right?
If you could help me I would appreciate it

Click here to see answer by stanbon(75887)

Question 439699: write varible expression please
Buffy deposits $700 in a college fund with a balance of B. How much money does Buffy have in her account?
Click here to see answer by asuar010(338)

Question 439781: one term of (5m+7n)^8 contains m^5. what is the exponent of n in that term? what is the coefficient of the term?
Click here to see answer by stanbon(75887)

Question 439793: Find the next 2 numbers in this sequence: 3, 3, 5, 6, 8, 12, 12, 24, 17
Click here to see answer by jorel1380(3719)

Question 439933: Hello, how many terms of the sequence -19,-15,-11,... must be taken to give a sum of 98? Thanks :)
Click here to see answer by stanbon(75887)

Question 440227: What number is described by the facts below?
Fact: The number is an integer.
Fact: The cube of the number is less than 50,000.
Fact: The square of the number is greater than 1,250.

Click here to see answer by rwm(914)

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