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 1013619: 5*5+7*7-9*9=100
Click here to see answer by fractalier(6550)

Question 1013535: Show that the sum of nth term of the series log3+log6+log12+.... Is nlog3+n(n-1)log2/2
Click here to see answer by richard1234(7193)

Question 1013535: Show that the sum of nth term of the series log3+log6+log12+.... Is nlog3+n(n-1)log2/2
Click here to see answer by Edwin McCravy(20056)

Question 1012868: (x-(-y))-(-(x^2-(-xy)-(-y^2)))-(-(x^3-(-x^2y)-(-xy^2)-(-y^3)))-.........
find the sum of n terms of this series.

Click here to see answer by Edwin McCravy(20056)

Question 1013968: 7, 64, 520, 4168 find the rule for this sequence
Click here to see answer by macston(5194)

Question 1013967: What is the sum of this infinite geometric series 1-1/3+1/9-...
Click here to see answer by ikleyn(52788)

Question 1013989: what is the general form of 0,2,6,12,20,30,42,.....
Click here to see answer by Theo(13342)

Question 1014011: What is the formula for the sequence 5,5,35,65,275. . .
Click here to see answer by Edwin McCravy(20056)

Question 1014131: Determine the 7th term of 6;12;24.
Show all your workings
Click here to see answer by ikleyn(52788)

Question 1014131: Determine the 7th term of 6;12;24.
Show all your workings
Click here to see answer by MathTherapy(10552)

Question 1014144: What is the first three terms of n+3

Click here to see answer by ikleyn(52788)

Question 1014269: please may u help me with this question... which term of the geometric sequence 2;6;18...is equal to 4374? please help
Click here to see answer by ikleyn(52788)

Question 1014247: what is the next number in the sequence 77 49 36
Click here to see answer by ikleyn(52788)

Question 1014367: The middle term of an arithmetic series of 31 terms is 50.determine the sum of the series.
Click here to see answer by ikleyn(52788)

Question 1014351: Thr 20th term of an arithmetic progression is 10 and the 50th term is 70, find the first term and the common difference

Click here to see answer by ikleyn(52788)

Question 1014387: Find 5 consecutive terms of an arithmetic progression whose sum is 115 and sum of squares of its second and fourth term is 1156.
Click here to see answer by ikleyn(52788)

Question 1014335: 16 06 68 88 ? 89
Click here to see answer by Edwin McCravy(20056)

Question 1014447: If a,b,c are in an arithmetic progression and x,y,z are in a geometric progression, prove that (x^b)(y^c)(z^a)=(x^c)(y^a)(z^b)
Click here to see answer by ikleyn(52788)

Question 1014480: what is the similarity with the numbers 85,19,17,4 and 2?
Click here to see answer by ikleyn(52788)

Question 1014480: what is the similarity with the numbers 85,19,17,4 and 2?
Click here to see answer by Alan3354(69443)

Question 1014548: Find the ninth term in this series.
-2, 5, 17
Click here to see answer by ikleyn(52788)

Question 1014538: the 5th term is 26 . the sum of the 8 terms is 184. what is the value of a and d?
Click here to see answer by ikleyn(52788)

Question 1014497: what is the similarity between the numbers 85, 17, 19, 4 and 2 ?
Click here to see answer by ikleyn(52788)

Question 1014496: What is the similarity between the numbers, 87,19,17,4 and 2

Click here to see answer by ikleyn(52788)

Question 1014652: Transpose a+x/a-x=b-y/b+y to make x the subject
Click here to see answer by josgarithmetic(39618)

Question 1014718: Three consecutive even numbers are such that the sum of the first two is 20 more than the third. Find them.
Click here to see answer by Fombitz(32388)

Question 1014698: What is the similarity between 85, 17, 19, 4, & 2 ?
Click here to see answer by Alan3354(69443)

Question 1014730: What's the next letter in his sequence mfmt
Click here to see answer by ikleyn(52788)

Question 1014931: What is the similarity between numbers 85,17,19,4,2
Click here to see answer by Alan3354(69443)

Question 1015023: If (x+1), (-2x+4) and (x+15) are 3 consecutive terms of an arithmetic sequence, determine x and the next 2 terms.
Click here to see answer by ikleyn(52788)

Question 1015081: if the consecutive integers from 1 is arranged serially. then the digit at 31st place is_______
Click here to see answer by ikleyn(52788)

Question 1012797: what would the explicit equation be for the sequence 117, 23.4, 4.68, �
Click here to see answer by Edwin McCravy(20056)

Question 1014477: can we take m^2-n^2 common from (2a-d)(m^2-n^2))+d(m^3-n^3)
Click here to see answer by Edwin McCravy(20056)

Question 1015257: if Tn =2- 3 which term of sequence is.
(a) - 43
(b) - 82

(c) 91
Click here to see answer by algebra hello(55)

Question 1015443: Please help with this question.how many terms in the series 19+16+13+...must be added to give a sum of 44?
Click here to see answer by rothauserc(4718)

Question 1015486: The fifth term of an arithmetic sequence is 23 and the 12th term is 72.
1.1determine the first three term of the sequence and the nth term.
1.2what is the value of the tenth term?
1.3which term is equal to 268?
Click here to see answer by Boreal(15235)

Question 1015559: Here is the question and I get it wrong not sure why,
1+2X3+4X5+6.
My answer is 33
Many others say 71.
Why?
Click here to see answer by ikleyn(52788)

Question 1015559: Here is the question and I get it wrong not sure why,
1+2X3+4X5+6.
My answer is 33
Many others say 71.
Why?
Click here to see answer by stanbon(75887)

Question 1015562: 7,14,23,34,?
Click here to see answer by Edwin McCravy(20056)

Question 1015562: 7,14,23,34,?
Click here to see answer by ikleyn(52788)

Question 1015886: The sequence 15,30,45,60 looks like 1,2,3,4 except each term is 15 times as long. So the formula 15n,where n represent the position of a term in the sequence.
Click here to see answer by Alan3354(69443)

Question 1015923: The forth term of the geometric sequence is 1/2 and the eleventh term is 1/512 so the question says determine the sum of the first and the third terms
Click here to see answer by Boreal(15235)

Question 1015861: The nth term of a sequence is n2-6n-4. Find the sum of 3rd and 4th terms
Click here to see answer by fractalier(6550)

Question 1015863: Find d in the AP given the nth term 16-6n
Click here to see answer by Herdaysoji(25)

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