Questions on Algebra: Sequences of numbers, series and how to sum them answered by real tutors!

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Question 849306: An infinite geo series has the sum 16. If the sum of the first two terms is 15, find a1 and r

Click here to see answer by AnlytcPhil(1806)

Question 849684: Mike started a savings account by depositing $9. Each month he deposits more money than the month before. At the end of 41 months, he has saved $9,989.00. How much more does he deposit each month?
Click here to see answer by swincher4391(1107)

Question 845949: Next number in sequence
3, -6 , 12, 4, 20
7, 16, 8, 27, 9
2, 7, 26, 101, 400
7, 21, 8, 72, 9
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Question 849725: In an arithmetic series, the terms of the series are equally spread out. For example, in
1 + 5 + 9 + 13 + 17, consecutive terms are 4 apart. If the first term in an arithmetic series is
3, the last term is 136, and the sum is 1,390, what are the first 3 terms?
Click here to see answer by swincher4391(1107)

Question 848420: Given the initial terms of the sequence a � b,2a,3a + b,�
Determine its 10th term.Determine its sum up to its 10th term
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Question 849757: explain why (-8)1/2 is not equal -(8)1/2, but (-27)1/3 is equal -(27)1/3
Click here to see answer by stanbon(75887)

Question 849757: explain why (-8)1/2 is not equal -(8)1/2, but (-27)1/3 is equal -(27)1/3
Click here to see answer by richwmiller(17219)

Question 849757: explain why (-8)1/2 is not equal -(8)1/2, but (-27)1/3 is equal -(27)1/3
Click here to see answer by MathTherapy(10552)

Question 849942: The first term of a geometric sequence is 3. The sum of the first three terms is 129. Find the possible values of the common ratio.
Click here to see answer by AnlytcPhil(1806)

Question 849893: From A(0,1),B(2,1),C(4,3) and D(-2,5). Find the values of r and s if rAD + sCD =AB
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Question 850063: 23, 26, 30, 35....is the number of seats in a row of a theatre. 23 being the first row, 26 being the second and so on. give a general solution for the number of seats in the nth row ?
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Question 850171: The first term is 3.To get the next term,you square the previous term and subtract 2.What is the general rule?
Click here to see answer by Nurply(1)

Question 850177: The fifth term of a geometric sequence is 1⁄108 and the common ratio is 1⁄3. The first term to this is?
Click here to see answer by josgarithmetic(39618)

Question 850176: What is the common ratio in the sequence 12, -18, 27, �
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Question 850548: Calculate the product of 1/8 and 1/7
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Question 850436: What is the first five terms and the explicit formula to a11= 14 and a39= 98
Click here to see answer by richwmiller(17219)

Question 849852: The tenth term of an arithmetic sequence is 42 more than the seventh term .If the first term is -14,find the second term?
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Question 847949: what is the common difference of tn=5n+3
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Question 850174: Find the 31st term in the sequence whose general term is an = -3 + 4(n - 1).
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Question 850170: The first term is 3.To get the next term,you square the previous term and subtract 2. What is the general rule?
Click here to see answer by richwmiller(17219)

Question 849570: what is the nth term of the sequence 12,6,3,1.5
Click here to see answer by richwmiller(17219)

Question 849890: The current value of a vehicle is sh.128000.If this vehicle has been depreciating by 1/5 of its value every year. Find its value four years ago?
Click here to see answer by hamsanash1981@gmail.com(151)

Question 850721: please help
Find the 4th term of the sequence an = 1000 (0.1)^n-1
Click here to see answer by Fombitz(32388)

Question 850716: Rewrite the following series in summation notation
3 + 12 + 48 + 192 + 768

Click here to see answer by Fombitz(32388)

Question 850797: Help!! Robin bought a computer for $1,250. It will depreciate, or decrease in value, by 10% each year that she owns it. A) Is the sequence formed by the value at the beginning of each year arithmetic, geometric, or neither? Explain. B) write an explicit formula to represent the sequence. C) find the value of the computer at the beginning of the 6th year.
Click here to see answer by josmiceli(19441)

Question 850841: Find dy/dx for the follwing

a=4
b=8
Click here to see answer by ewatrrr(24785)

Question 850886: if the 2nd and 5th term of a G.P are -6 and 48 respectively,find the sum pf the first four term
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Question 850902: simplify: (4n^-2u^-3)^2
Click here to see answer by lwsshak3(11628)

Question 851010: what is the value of n when 8n-14=6n+6?
Click here to see answer by jim_thompson5910(35256)

Question 851136: Find the fifth term of a geometric sequence whose fourth term is

16/27 and whose seventh term is 128/729.

Click here to see answer by ewatrrr(24785)

Question 851217: PLEASE HELP!!!!! Dante is making a necklace with 18 rows of tiny beads in which the number of the beads per row is given by the series 3+10+17+24+.... A) use summation notation to write the series. Explain what the numbers in the summation notation represent in this situation and how you found the expression used in the summation. B) find the total number of beads in the necklace. Explain your method for finding the total number of beads
Click here to see answer by ewatrrr(24785)

Question 851214: Please help me with this question!!!! The number of seats in the first 12 rows of a high school auditorium form an arithmetic sequence. The first row has 9 seats. The second row has 11 seats. A) write a recursive formula to represent the sequence. B) write an explicit formula to represent the sequence. C) how many seats are in the 12th row?
Click here to see answer by richwmiller(17219)

Question 850795: Please help!!!!! The number of seats in the first 12 rows of a high school auditorium form an arithmetic sequence. The first row has 9 seats. The second row has 11 seats. A) write a recursive formula to represent the sequence. B) write an explicit formula to represent the sequence. C) how many seats are in the 12th row?
Click here to see answer by richwmiller(17219)

Question 851203: Determine a 5th term in the sequence 77,49,36,18...
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Question 851203: Determine a 5th term in the sequence 77,49,36,18...
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Question 845182: 3x-1/4 ;2x-1/3 ;7x-5/12
Prove that these are terms of an arithmetic sequence
Click here to see answer by richwmiller(17219)

Question 846904: sum of the first 17 terms is 2414
last term is 256 what is the first term?
Click here to see answer by richwmiller(17219)

Question 845095: what are the next 5 terms in this equation
a1=3/4,d=1/-4
Click here to see answer by richwmiller(17219)

Question 851360: how do you calculate the difference of 2/3-5/9?
Click here to see answer by richwmiller(17219)

Question 851360: how do you calculate the difference of 2/3-5/9?
Click here to see answer by josmiceli(19441)

Question 850798: Dante is making a necklace with 18 rows of tiny beads in which the number of beads per row is given by the series 3 + 10 + 17 + 24 + ....
A) use summation notation to write the series. Explain what the numbers in the summation notation represent in this situation and how you found the expression used in the summation.
B) find the total number of beads in the necklace. Explain your method for finding the total number of beads.
Click here to see answer by richwmiller(17219)

Question 851021: Find the sum of the first 8 terms in the geometric series 1-4+16-64+...

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Question 850722: Find the 7th term of the series 9,-6,4.
Kraaigp@gmail.com
Click here to see answer by richwmiller(17219)

Question 850720: please help
Given that the first term of a geometric sequence is -320 and seventh term is -3645, the common ratio to the nearest tenth is?
Click here to see answer by richwmiller(17219)

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