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 1061725: find the sum if it exists
25+5+1+...
Click here to see answer by Edwin McCravy(20056)

Question 1061703: 3, -6, 12, 4, 20, ?
Click here to see answer by Edwin McCravy(20056)

Question 1061795: 4,13,38........ Next term
(A) 58 (B)96. (C) 111 (D) 123

Click here to see answer by rothauserc(4718)

Question 1061883: 1-(1/4)+(1/9)-(1/16)+(1/25)-............=?

Click here to see answer by rothauserc(4718)

Question 1061883: 1-(1/4)+(1/9)-(1/16)+(1/25)-............=?

Click here to see answer by ikleyn(52788)

Question 1061967: What is the next number: 5,2,631,5,7,89,47,3,?
Click here to see answer by Alan3354(69443)

Question 1061966: What is the next number: 2,2,3,6067,97,7,499,7
Click here to see answer by Alan3354(69443)

Question 1062031: Prove that
for .
Click here to see answer by Edwin McCravy(20056)

Question 1062148: 100, 20, 4, 4/5...
what are the nest three terms in the sequence
Click here to see answer by jorel555(1290)

Question 1062147: -1, 4, -9, 16, -25
what are the nest three terms of the sequence

Click here to see answer by jorel555(1290)

Question 1061702: 2, 7, 26, 101, 400, ?
Click here to see answer by Edwin McCravy(20056)

Question 1062189: The sum of first four terms of GP is 30 and that of the last four terms is 960. If the first and last term of GP are 2 and 512 respectively, find the common ratio.
Click here to see answer by ikleyn(52788)

Question 1061052: Can I know what particular equation can I use to find the nth term of this sequence? 5,12,31,68,129
Click here to see answer by Edwin McCravy(20056)

Question 1062254: What is the value of 1+cos^1x+cos^2x+cos^3x+cos^4x+..........to infinity?
Click here to see answer by ikleyn(52788)

Question 1062255: The two successive terms in the expansion of (1+x)24 whose coefficients are in the ratio 1:4 are?
Click here to see answer by ikleyn(52788)

Question 1062258: Hello could you please help me with these questions, I would really appreciate it if you could.
What is the nth term in this sequence 2, 9, 28, 65
Then what is the 10th term in the sequence.
And the last one what are the first four terms in 3(n+1)
Thank you for your help.
Click here to see answer by rothauserc(4718)

Question 1062296: Hi, can you please help me how to get the correct answer on this. Thank you!

Click here to see answer by ikleyn(52788)

Question 1062323: Hi, please help me turn this series into summation notation. Thank you in advance.
1. 2!/7 + 3!/14 + 4!/21 + ... + (n-1)!/7n
2.
Click here to see answer by Boreal(15235)

Question 1062323: Hi, please help me turn this series into summation notation. Thank you in advance.
1. 2!/7 + 3!/14 + 4!/21 + ... + (n-1)!/7n
2.
Click here to see answer by MathTherapy(10552)

Question 1062326: Select the option for �?� that continues the pattern in the question.
3, -6, 12, 4, 20, ?

Click here to see answer by Edwin McCravy(20056)

Question 1062365: Write each sum using summation notation
1. 2!/7 + 3!/14 + 4!/21 + ... + (n+1)!/7n
Thank you in advance and Merry Christmas!
Click here to see answer by ikleyn(52788)

Question 1062406: Hi, please help me solve this. Thank you and have a good day.
A homeowner has kept records of the average monthly electric bill for 4 yrs.
Year |Amount ($)
1 |102.60
2 |108.00
3 |113.40
4 |118.80
a. Do the average monthly electric bills follow an arithmetic progression?
b. Write an expression for the nth term of the sequence.
c. Predict the average monthly bill for year 6 if this trend continues.
Click here to see answer by josmiceli(19441)

Question 1062404: Please could you help find the rule of such a sequence:
72, 24, 12, 6, 4, 3, 2, 2...
What is the next number?
Thanks in advance,
Vlad
Click here to see answer by chen.aavaz(62)

Question 1062585: Tn=-4
T23=1
Tn=T(n-1)-3
n=?
Click here to see answer by ikleyn(52788)

Question 1062558: I'm wondering: what is the sixth term in this sequence: -1, 0, 0, 2, 10, ??
Thank you!
Click here to see answer by Edwin McCravy(20056)

Question 1062558: I'm wondering: what is the sixth term in this sequence: -1, 0, 0, 2, 10, ??
Thank you!
Click here to see answer by ikleyn(52788)

Question 1062612: The third term of an A.P. is 4 more than twice the first term.
The 8th term is 4 less than "trice" the third term. Find the fifth
term of the ap

Click here to see answer by Edwin McCravy(20056)

Question 1062664: Please could be found the rule of such a sequence:
72, 12, 6, 4, 3, 2, 2 ?
Please don't modify the given series.
The similar problem with 79, 24, 12... is much easier.
What might be the next number?
Thanks in advance,
Vlad
Click here to see answer by Edwin McCravy(20056)

Question 1060263: Henry deposits $300 each month into an account paying annual interest of 8% compounded monthly. How much will his account have in it at the end of 16 years?
A. $116,162.74
B. $110,765.08
C. $51,073.38
D. $91,074.59
Click here to see answer by addingup(3677)

Question 1062748: Here is my problem: There are two geometric sequences with 3rd term 5 and 5th term 80. What are the two possible values of the 4th term?
I have my two equations of
5=ar^2
80=ar^4
(a is first term and r is mutliplier quantity)
I then go to 80/5 = r^4/r^2 which then ends up being 16r = r^2 and over to r^2 - 16r = 0. Completing the square gives me r^2 - 16r + 64 = 64. Problem is that then gets me right back to my pre-completing the square part. My other option is to do r(r-16) = 0 which gives me r = 0 and 16 which can't work because r = 0 doesn't give me any workable answer. So I must assume I'm doing something wrong.
Thanks for any help!
Click here to see answer by jim_thompson5910(35256)

Question 1062762: Three numbers are in AP such that their sum is 18 and sum of their squares is 158 the greatest number among them is
Click here to see answer by ikleyn(52788)

Question 1062750: Write a program to print the following series
2 5 11 17 23 31 41 47 59 ...

Click here to see answer by rothauserc(4718)

Question 1062750: Write a program to print the following series
2 5 11 17 23 31 41 47 59 ...

Click here to see answer by Edwin McCravy(20056)

Question 1062792: rewrite series as sigma notation
1) 9+16+25+36
Click here to see answer by math_helper(2461)

Question 1062804: find the nth term of this sequence:
-1/3,1/9,-1/27,1/81,.....
Click here to see answer by jim_thompson5910(35256)

Question 1062804: find the nth term of this sequence:
-1/3,1/9,-1/27,1/81,.....
Click here to see answer by Edwin McCravy(20056)

Question 1062796: rewrite series as sigma notation
1) 25+36+49+64+81
2) 0+1+4+9
Click here to see answer by Edwin McCravy(20056)

Question 1062808: find the fifth term, the nth term, the 100th term of this arithmetic sequence:
1) 2,5,8,11,...
2) 1,5,9,13,..
3) 4,9,14,19,..
Click here to see answer by ikleyn(52788)

Question 1062828: what are the next three sequence after 3 12 27 48?
Click here to see answer by josgarithmetic(39618)

Question 1062834: write a c progaram to print the following series 2 5 11 17 23 31 41 47 59

Click here to see answer by solver91311(24713)

Question 1062910: what is the general term of -2,-5,-8,-11.....
Click here to see answer by ikleyn(52788)

Question 1062939: What if you only know the 1st and 3rd value of a term value and you need to find the arithmetic explicit equation. How would you find the multiplier? What is the tactic to find that value without the guess and check method? Thank you very much. The table is down below.
__n__|_t(n)_
__1__|__17__
__2__|______
__3__|___3__
__4__|______

Click here to see answer by rothauserc(4718)

Question 1062907: Next number in sequence for the following:
7 16 8 27 9
3 -6 12 4 20
2 7 26 101 400
7 21 8 72 9
Click here to see answer by Edwin McCravy(20056)

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