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 1094620: how do you solve arithmetic sequence problems..
find the sum of the terms of the arithmetic sequence.
1, 6, 11, 16, . . ., 116 n = 24
Click here to see answer by greenestamps(13200)

Question 1094581: What two numbers come next and why ?
5,3,1,7,7,8,7,4,4,2,__,__
Click here to see answer by greenestamps(13200)

Question 1094688: Find the indicated sum.
5, 15, 45, 135, 405, . . . ; S14
Click here to see answer by Edwin McCravy(20056)

Question 1094697: Find the sum of the first 28 terms of the sequence {an} = {8n+2}
Click here to see answer by greenestamps(13200)

Question 1094701: what is the formula for find a40 for the sequence with a1 = 17 and d=6, and how do you complete the steps. Thank you
Click here to see answer by Edwin McCravy(20056)

Question 1094701: what is the formula for find a40 for the sequence with a1 = 17 and d=6, and how do you complete the steps. Thank you
Click here to see answer by math_helper(2461)

Question 1094708: Find a10 for the sequence with a1 = 3 and r=2
Click here to see answer by ikleyn(52787)

Question 1094708: Find a10 for the sequence with a1 = 3 and r=2
Click here to see answer by jim_thompson5910(35256)

Question 1094652: (2a+b)/(a+4b)=3 if (a+b)/(a+2b)=?
Click here to see answer by richwmiller(17219)

Question 1094652: (2a+b)/(a+4b)=3 if (a+b)/(a+2b)=?
Click here to see answer by ikleyn(52787)

Question 1094751: Etermine the number of terms in the sequence -16,-12,-8,...,60
Click here to see answer by ikleyn(52787)

Question 1094751: Etermine the number of terms in the sequence -16,-12,-8,...,60
Click here to see answer by MathTherapy(10552)

Question 1094751: Etermine the number of terms in the sequence -16,-12,-8,...,60
Click here to see answer by greenestamps(13200)

Question 1094753: The six term of an arithmetic progression is 23 and the sum of the first six terms is 78.Find
(a)the common difference and the first term
(b)the tenth term
Click here to see answer by ikleyn(52787)

Question 1094750: The sum of the first twenty terms in an arithmetic progression is 840 and the common difference is 4.Find
(a)the first term
(b)the sum of the first ten terms
Click here to see answer by josgarithmetic(39617)

Question 1094756: In an arithmetic sequence,the sum of the first twelve terms is 156 and 4th term is 8.Find
(a)the first term and the common difference
(b)the sum of the first sixteen terms

Click here to see answer by greenestamps(13200)

Question 1094743: What is the smallest integer that can possibly be the sum of an infinite geometric series whose first term is 9?
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Question 1094808: If the sum of three number in geometric series is 14 and their product is 64.find the number
Click here to see answer by ikleyn(52787)

Question 1094808: If the sum of three number in geometric series is 14 and their product is 64.find the number
Click here to see answer by greenestamps(13200)

Question 1094817: the 100th term of 70,100,130.

Click here to see answer by ikleyn(52787)

Question 1094848: What is Third Number among Following List ?
16, 47, 83
Click here to see answer by ikleyn(52787)

Question 1094847: t is Third Number among Following List ?
16, 47, 83
Click here to see answer by ikleyn(52787)

Question 1094897: Trying to figure out the missing number for 56,_12>56,396 and the answer are 1 2 3 4
Click here to see answer by greenestamps(13200)

Question 1094949: Determine the value of t1 for an arithmetic sequence, where d = �4 and S14 = 1 120
Ive been having so much trouble trying to figure out how to find t1 without Tn or n.
(d= change in each term
S14=sum of the 14th term)
Click here to see answer by ikleyn(52787)

Question 1094971: Find a Geometric series with first term 1 and common ratio -2
Click here to see answer by ikleyn(52787)

Question 1095552: Describe the pattern in the sequence and find the next three terms.
4, 8, 16, 32, ...
Click here to see answer by 34(1)

Question 1095552: Describe the pattern in the sequence and find the next three terms.
4, 8, 16, 32, ...
Click here to see answer by ikleyn(52787)

Question 1095699: What numbers are next in the sequence 121314 and why
Click here to see answer by ikleyn(52787)

Question 1095698: What numbers are next in the sequence and why
Click here to see answer by ikleyn(52787)

Question 1095685: A geometric progression has 6 terms. The ﬁrst term is 192 and the common ratio is 1.5. Given that the sum of all the terms in the
geometric progression is equal to the sum of all the terms in the arithmetic progression, ﬁnd the ﬁrst
term and the last term of the arithmetic progression.
Click here to see answer by greenestamps(13200)

Question 1095895: I need help with this sequence. 2 7 8 3 12 9
Click here to see answer by ikleyn(52787)

Question 1095926: 093,951,993,878,599
Click here to see answer by ikleyn(52787)

Question 1096056: I have a problem with a sequence of dots. When n=1, there's one dot. When n=2, there's a shape that looks like a 2x2 rectangle made of 4 dots, and a triangle with 1 dot on top forming a "house looking shape" with 5 dots. When n=3, it's a 3x3 rectangle with a triangle with 3 dots. I think it might be easier to upload an image: https://imgur.com/a/g9UOx
Thank you!
Click here to see answer by greenestamps(13200)

Question 1096099: find x in the series 1+4+7+...+x=715
Click here to see answer by Boreal(15235)

Question 1096234: 7, 21, 8, 72, 9, ?
2, 7, 26, 101, 400, ?
Click here to see answer by Edwin McCravy(20056)

Question 1096240: 300 298 307 279 344 ?
Click here to see answer by Edwin McCravy(20056)

Question 1096353: The sum of a set of five consecutive even numbers is 140. What is the sum of the next set of five consecutive even numbers?
Click here to see answer by josgarithmetic(39617)

Question 1096413: In a geometrical progression the sum of the 2nd and the 3rd terms is 6 and the sum of the 3rd and 4th term is -12.Find the 1st term and the common ratio.
Click here to see answer by KMST(5328)

Question 1096392: If geometrical progression is
2ki power 1upon4 into 4 ki power 1 upon 8
Into 8 ki power 1 upon 16into 16 ki power 1 upon
.............Infinite
Then prove that Sinfinity is equal to 2
Click here to see answer by Alan3354(69443)

Question 1096444: the 21st
Click here to see answer by richwmiller(17219)

Question 1096443: the 21st term
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Question 1096429: evaluate 1+3^2+3^3+..++..3^60 everything divided by 3^61-1
Click here to see answer by greenestamps(13200)

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