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 1068107: Write the explicit formula that represents the geometric sequence -2, 8, -32, 128

Click here to see answer by Edwin McCravy(20056)

Question 1068107: Write the explicit formula that represents the geometric sequence -2, 8, -32, 128

Click here to see answer by Fombitz(32388)

Question 1068219: continue the sequence 27,9,18,6,12,4,
Click here to see answer by math_helper(2461)

Question 1068007: The three consecutive term of an exponential sequence are the second, third and sixth term of a linear sequence, find the common ratio of g.p
Click here to see answer by Lightning_Fast(78)

Question 1066625: What is the next term in series derived and how
29,82,51,20,80,17,81,59,07
Click here to see answer by Lightning_Fast(78)

Question 1068283: Find n
When a=7,d=-4 and Tn=-97
Click here to see answer by ikleyn(52788)

Question 1068403: I need to find the next number in a sequence but it is really challenging.
1, 11, 21, 1211, 111221 are what I have to work with
Click here to see answer by rothauserc(4718)

Question 1068403: I need to find the next number in a sequence but it is really challenging.
1, 11, 21, 1211, 111221 are what I have to work with
Click here to see answer by ikleyn(52788)

Question 1068658: What is the next number in sequence 2, 7, 14, 9, 18,
Click here to see answer by ikleyn(52788)

Question 1068658: What is the next number in sequence 2, 7, 14, 9, 18,
Click here to see answer by Alan3354(69443)

Question 1068574: 7, 16, 8, 27, 9, ?
Click here to see answer by ikleyn(52788)

Question 1068729: How to calculate the number of terms if the first term in an arithmetic series is 2 the last term is 20 and the sum of all terms is 110
Click here to see answer by Boreal(15235)

Question 1068733: Determine the sum to 16 terms of the arithmetic series whose 7th term is 19 and whose 10th term is 25
Click here to see answer by swincher4391(1107)

Question 1068846: if 3,p,q,34 are consecutive terms of an A.P,find the values of p and q
Click here to see answer by htmentor(1343)

Question 1069078: the 5th term of an arithmetic sequence is 0 and the 13th term is equal to 12. Using suitable formulae determine the common difference,the first term,and the sum of the first 21 terms
Click here to see answer by rothauserc(4718)

Question 1069068: 1,3.5 are the first three terms of the differences of a quadratic sequence. the 7th term of the quadratic sequence is 35
a) determine the 6th and 5th terms of the quadratic sequence
b) determine the nth term of the quadratic sequence
Click here to see answer by ikleyn(52788)

Question 1069082: The 12th term of an arithmetic seqence progression is 5.the 7th term of this progression is 9 more than the 4th term. Determine the sum of 20 terms of this progression
Click here to see answer by ikleyn(52788)

Question 1069243: Find the range of values of x for which the infinite series 1 +
lnx/2 +(lnx)^2/(2^2) + (lnx)^3/(2^3) + (lnx)^4/(2^4)+... converges. Find the sum to infinity when x=e^(1/2).
Click here to see answer by trsomas23@gmail.com(17)

Question 1069274: in a mixture we know that we want 1% of a product that is made up of 50% of a particular ingredient. If another product were substituted that had 75% of that ingredient, what would we reduce the 1% of the new product to.
Click here to see answer by Boreal(15235)

Question 1069417: the sum of the n terms of a sequence is 30-10/3^(n-1); n>1
find (a) sum of the first five terms (b) fifth term; of the sequence
Click here to see answer by Edwin McCravy(20056)

Question 1069483: Insert 4 gm's between 3 and 729

Click here to see answer by Alan3354(69443)

Question 1069485: What term of the sequence 15,24,33,42......is 105
Click here to see answer by Fombitz(32388)

Question 1069534: How do I use the sigma notation to express the series :
2+1+1/2+1/4+1/8..............

Click here to see answer by Fombitz(32388)

Question 1069603: Three consecutive terms in an arithmetic sequence is given with a middle one x. The sum of the three terms is 30 and the product of the three terms is 840
Calculate the three terms
Click here to see answer by ikleyn(52788)

Question 1069598: If end=:5
Sequence:(r+b)=10a
Start:r=1
Write b in terms of a
Click here to see answer by ikleyn(52788)

Question 1069684: 2,10,25,?,81,132
Click here to see answer by Barangay i.d(1)

Question 1069759: What are the next three terms of the following sequence?
-2,-1,-1/2,-1/4

Click here to see answer by ikleyn(52788)

Question 1069752: Find s15 for the series -1+-3+-5+-7+...
Thanks!
Click here to see answer by ikleyn(52788)

Question 1069751: Find the sixth term of an arithmetic sequence with t1=2 and tn=tn-1+4
Thank you so much
Kim
Click here to see answer by Fombitz(32388)

Question 1069817: The sum of the first ten terms of a particular arithmetic sequence is four times the sum of the first five terms of the sequence. What is the ratio of the first term to the second term? Express your answer as a common fraction.
Click here to see answer by KMST(5328)

Question 1069822: Please find the nth term and sum of n terms of the series 3,7,14,27,52....help me with the details and step by step.
Click here to see answer by ikleyn(52788)

Question 1069822: Please find the nth term and sum of n terms of the series 3,7,14,27,52....help me with the details and step by step.
Click here to see answer by Alan3354(69443)

Question 1069898: If n(a) = 35 and n(b)=8 find the following if the sets A and B are disjoint:
a) n (A intersect B)
b) N (a union B)
Click here to see answer by ikleyn(52788)

Question 1069916: 1 + 1/3 + 1/(3*9) + 1/(3*9*27) + 1/(3*9*27*81) sum of this series ??

Click here to see answer by Edwin McCravy(20056)

Question 1070034: What's the common ratio of -5, 20, -80 i tried this An=A1*(r)^n-1

Click here to see answer by josgarithmetic(39618)

Question 1070034: What's the common ratio of -5, 20, -80 i tried this An=A1*(r)^n-1

Click here to see answer by MathTherapy(10552)

Question 1070031: find the sum of all 5 digit numbers that can be formed by using the digits 2,3,5,7 and 8, where each of these digits appears in each number.
Click here to see answer by Edwin McCravy(20056)

Question 1070098: How to find the sum of even numbers from 2 to 80?
Click here to see answer by josgarithmetic(39618)

Question 1070098: How to find the sum of even numbers from 2 to 80?
Click here to see answer by Alan3354(69443)

Question 1070097: Five years ago, a father was 3times as old as his son. Now,their combined ages amount to 110 year.what is the present age of the father.

Click here to see answer by josgarithmetic(39618)

Question 1070092: How many terms of the A.P 9,17,25,...Must be taken to give a sum of 636?
Click here to see answer by Fombitz(32388)

Question 1070103: I want to know what number follows the sequence 7,2,0,7,8,4,3
Click here to see answer by Edwin McCravy(20056)

Question 1069942: Find S15 for the series 1 + 1.5 + 2.25 + 3.375 +...
Click here to see answer by Fombitz(32388)

Question 1070095: The 12th 85th and last terms of an arithmetic progression are 38 257 and 395 respectively. Find the number of term.

Click here to see answer by Fombitz(32388)

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