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 1040203: 15+12+9+6...=-90 find number of terms

Click here to see answer by Fombitz(32388)

Question 1040396: Find the n th term of the following sequence:
5 + 55 + 555 + �.. (T)n
Click here to see answer by robertb(5830)

Question 1040521: 3=36,4=26,5=27,6=______
Click here to see answer by Aldorozos(172)

Question 1040568: WHAT are the answer and solution of the following 125,25,5,1
Click here to see answer by josgarithmetic(39618)

Question 1040619: 25 light poles are to be installed at equal intervals along a city street and at each end. If the
street is 1800 m long, how far apart should the poles be placed?
Click here to see answer by ikleyn(52788)

Question 1040618: I have problems I need help with for my nephew. They are figure out the next number.
12,20,4,2,14,3,23,10,2,10
25,27,22,23,40,27,29,34,24,28
37,36,24,41,42,36,37,39,31,32
60,41,31,53,43,56,60,59,57,61
69,58,33,63,52,69,64,63,66,64
20,7,10,11,17,25,6,4,18,12
Click here to see answer by josgarithmetic(39618)

Question 1040608: i was given the following sequence and I need the eight term but can't figure it out, these are the numbers -2, -4, -11, -20, -28, -32, -29
Click here to see answer by josgarithmetic(39618)

Question 1040752: If 15th and 11th term of an A.P are 3 and 23 respectively. Is 40 the term of the sequence ?
Click here to see answer by stanbon(75887)

Question 1040792: What is the common ratio of the following sequence: 1/2. -1/8. 1/14. -1/2
Click here to see answer by alyx_v(38)

Question 1040792: What is the common ratio of the following sequence: 1/2. -1/8. 1/14. -1/2
Click here to see answer by ikleyn(52788)

Question 1040793: Find two positive numbers such that the sum of the squares of the two numbers is 245 and the difference between the two numbers is 7.
Click here to see answer by ikleyn(52788)

Question 1040821: Evaluate:
∞
Σ (1/3)(-4/3)^k
k=1
I hope I asked this right, the infinite is on top of the sigma. K=1 is on the bottom. And the rest is to the right of the sigma. Thank you! Just want to check my answer, haven't done sequences since high school.
Click here to see answer by jim_thompson5910(35256)

Question 1040829: If the sixth term of a sequence is 128 and the common ratio is 2, what is the first term?
Click here to see answer by stanbon(75887)

Question 1040843: Which nth term of the arithmetic sequence 2,7,12 is 152
Click here to see answer by rothauserc(4718)

Question 1040969: The interior angles of a polygon are in arithmetic progression.the smallest angle is 52 degree and the common difference is 8 degree.find the number of sides of the polygon.

Click here to see answer by Alan3354(69443)

Question 1041158: Need help using Sigma Notion to represent this series,
2 + 5 + 8 + 11 + 14 + 17
Solutions in Sigma Notion: https://postimg.org/image/z9biwjgjr/
Ty
Click here to see answer by jim_thompson5910(35256)

Question 1041160: What is the sum of this arithmetic series?
https://postimg.org/image/p3law3x9z/
A.) 25
B.) 126
C.) 133
D.) 119
Please & TY!
Click here to see answer by jim_thompson5910(35256)

Question 1041160: What is the sum of this arithmetic series?
https://postimg.org/image/p3law3x9z/
A.) 25
B.) 126
C.) 133
D.) 119
Please & TY!
Click here to see answer by ikleyn(52788)

Question 1041149: What is the sum of this arithmetic series?
https://postimg.org/image/p3law3x9z/
A.) 25
B.) 126
C.) 133
D.) 119
Click here to see answer by jim_thompson5910(35256)

Question 1041232: Find the value of x if the arithmetic mean of 3 and 3x+5 is 8
Please help and explain how to
Thank you in advance
Click here to see answer by Alan3354(69443)

Question 1041231: Find x if the sequence m,x,n is an arithmetic
Please help and explain how to
Thank you in advance :)
Click here to see answer by josgarithmetic(39618)

Question 1041231: Find x if the sequence m,x,n is an arithmetic
Please help and explain how to
Thank you in advance :)
Click here to see answer by ikleyn(52788)

Question 1041231: Find x if the sequence m,x,n is an arithmetic
Please help and explain how to
Thank you in advance :)
Click here to see answer by MathTherapy(10552)

Question 1041236: Find S24 for the sequence 2,14,...12n-10
Thank you in advance
Click here to see answer by jim_thompson5910(35256)

Question 1041235: Find the sum of the first n positive even integer
Thank you in advance
Click here to see answer by ikleyn(52788)

Question 1041318: If S8 = 1530 and r = 2, what is a1?
3
6
9
12
Click here to see answer by Theo(13342)

Question 1041318: If S8 = 1530 and r = 2, what is a1?
3
6
9
12
Click here to see answer by jim_thompson5910(35256)

Question 1041280: What will be the next number and how?
73, 298, 475, 544,688,
Click here to see answer by Edwin McCravy(20056)

Question 1041280: What will be the next number and how?
73, 298, 475, 544,688,
Click here to see answer by ikleyn(52788)

Question 1041348: (x+y-2z)^2+2(x+y-2z)(x-2y+2z)+(x-2y+2z)^2
Click here to see answer by Edwin McCravy(20056)

Question 1041358: Find two consecutive odd number whose product is 483
Click here to see answer by Alan3354(69443)

Question 1041397: A contestant on a quiz show wins $100 for answering the first question correctly, $200 for answering the second question correctly, and so on, winning twice as much for each CORRECT answer as for the previous CORRECT answer. Alvin answered eight consecutive questions correctly. What is the number of dollars he won?
Answer: $25,500 (How?)
Click here to see answer by Fombitz(32388)

Question 1041517: S8= 2250, r= 2, A3= ?
Click here to see answer by stanbon(75887)

Question 1041613: How many terms ofthe sequence -24, -15, -6, and 3 will give a sum of 1230?

Click here to see answer by Fombitz(32388)

Question 1041613: How many terms ofthe sequence -24, -15, -6, and 3 will give a sum of 1230?

Click here to see answer by ikleyn(52788)

Question 1041613: How many terms ofthe sequence -24, -15, -6, and 3 will give a sum of 1230?

Click here to see answer by MathTherapy(10552)

Question 1041559: 3,6,7,-2
Click here to see answer by Edwin McCravy(20056)

Question 1041784: The following letters represent a series. What letter do you think comes next?
I, O, V, F, X, T, L, F, M, _
Click here to see answer by Edwin McCravy(20056)

Question 1041598: Given the geometric sequence an = 4(6)n − 1, which of the following values for n lies in the appropriate domain for n?
Click here to see answer by Edwin McCravy(20056)

Question 1041917: Michael saved $50 in January.Suppose he saved twice the amount he saved the previous month.How
Much would he save at the end of one year?
Click here to see answer by jorel555(1290)

Question 1042037: Find sum of 9 terms in a
arithmetic sequence is 207 sum of first 20 terms
is 900 . Find fifth and twenty fifth term Find
the sum of 100 terms
Click here to see answer by stanbon(75887)

Question 1042084: Andrew thinks of 4 consecutive numbers. The sum of the first three numbers is 100 more than the fourth number. What is the sum of these four consecutive numbers?
Click here to see answer by solver91311(24713)

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