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 951124: Find the common difference of the arithmetic sequence whose second term is 6 and sixth term is 61.
Click here to see answer by Fombitz(32388)

Question 949999: find next term 16,12,28,8,4?? plz explain ans is 40 but how??
Click here to see answer by Edwin McCravy(20056)

Question 951848: The mean of six numbers is 24. Five of the numbers are 18, 30, 27, 25 and 29. What is the missing number?
Click here to see answer by macston(5194)

Question 952397: 1 3 5 7 9 11 13 15 how to Add any three numbers to get 30. Only simple adding.
Click here to see answer by Alan3354(69443)

Question 952846: Write the series with summation notation:
-1+8-27+64-125
Click here to see answer by Edwin McCravy(20056)

Question 953059: The sides of a rectangle are consecutive numbers.if the perimeter of a rectangle is 146 cm,find the length of the sides
Click here to see answer by checkley77(12844)

Question 953162: Q+7/15=4/5 how do you solve and what is the answer?
Click here to see answer by rfer(16322)

Question 953175: 3x-4;4x-2 and 7x-6 form an arithmetic sequence. Determine x and hence the three terms
Click here to see answer by MathLover1(20850)

Question 953227: the square root of 100-4x= 3 (to the second power)- (x+5)
Click here to see answer by josgarithmetic(39617)

Question 953367: In G.P the first term is 153 and the sixth term is 17/27 find the sum of the first four terms
Click here to see answer by Frosty7(4)

Question 953362: Find the eleventh term of the progression 4,8,16---
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Question 953478: What is the value of the 8th term in a geometric progression with first term 20 and common ratio 1 / 3
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Question 953111: How many terms are there is the geometric progression 2,4,8............128?
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Question 953197: what is the summation notation for -2+4-8+16-32

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Question 953484: 3,1,-1,-3

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Question 953579: Find an nth term formula for the sequence: 50, 46, 42, 38, 34, 30,...
I notice the pattern subtracts by four.
I am stuck. My instructor did not explain this well. He described mostly increasing numbers.
Click here to see answer by josgarithmetic(39617)

Question 953582: An amphitheater has 22 seats in the first row and 40 rows in all. Each successive row has one additional seat. How many seats are in the amphitheater?
I believe 1660 seats but I did a long explanation of this and don't know a way to find it easier I made a list adding one to every number for 40 rows excluding the first one.
Click here to see answer by Theo(13342)

Question 953581: If the 4th term of an arithmetic sequence is 3 and the 20th term is 35, find the 100th term of the sequence.
I believe the equation = -5 + 2n
and maybe the 100th number is 95
It does not make senses to me.
Click here to see answer by rothauserc(4718)

Question 953598: Decreasing or increasing ? an=ne^-n
I need not only answer but explanation too.
Click here to see answer by Theo(13342)

Question 953629: Given the arithmetic sequence:7;2:-3...determine the nth term
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Question 953904: Find k,given that 32,k,3; are consecutive terms of an arithmetic sequence
Click here to see answer by MathLover1(20850)

Question 954182: If .5 equals 70% , what does 30% equal?
Click here to see answer by Fombitz(32388)

Question 954019: -22,-26,-30,-34
Write a rule for the nth term of the arithmetic sequence
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Question 954448: 1+5+14+30+55........
Find sum to n terms.
Click here to see answer by hemu_da(13)

Question 954578: 340 tickets divide by 3
A has 80 more than B
B has 40 more than C
How many tickets do each have?
Click here to see answer by rfer(16322)

Question 71405: sum the series
1+4/6 + 4.5/6.9 + 4.5.6/6.9.12 + ................infinity
Click here to see answer by hafys14feb(1)

Question 955356: Find the 300th term of the sequence 5, 8, 11, 14, 17
Click here to see answer by josmiceli(19441)

Question 955461: The common ratio of a geometric sequence is -3. If the terms of these sequence are 3y, y+6, a+1, ..., respectively. What is the value of a?
Click here to see answer by josgarithmetic(39617)

Question 955491: Find the third term of a geometric sequence whose first term is 3 and whose fifth term is 768.
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Question 955491: Find the third term of a geometric sequence whose first term is 3 and whose fifth term is 768.
Click here to see answer by MathTherapy(10552)

Question 955609: Which of the following numbers is NOT between �1 and 1?
6/7
�29/30
5/8
�7/10
�9/4

Click here to see answer by Zucchini(70)

Question 955505: if sn the sum of first n terms of an AP is given by Sn=3nsq-4n then find nth term

Click here to see answer by KMST(5328)

Question 955773: The perimeter of a triangle is 30 units.The length of the sides form an arithmetic sequence.if each length is a whole number,determine all possible sets of the lengths of the sides of the triangle.
Click here to see answer by MathLover1(20850)

Question 955913: Find all values of x so that 6x, 4x-1, x^2-1 will be ab arithmetic sequence.
Here is what I did:
6x/a1, 4x-1/a2, x^2-1/a3
a2 - a1 = a3 - a2
(4x-1) - (6x) = (x^2-1) - (4x-1)
4x-1-6x = x^2-1-4x+1
-1-2x = x^2 - 4x
0 = x^2 - 4x +2x + 1
0 = x^2 - 2x + 1
0 = (x-1)(x-1) ..... from here, what do I do now to get the value of x? Am I on the right track?
Click here to see answer by stanbon(75887)

Question 956146: 4(3x + 5) = 3( x -2)-10?
Click here to see answer by Fombitz(32388)

Question 956094: Find 2 geometric means between 9 and -1944

Click here to see answer by Edwin McCravy(20056)

Question 956201: what comes after 3.5,13,41.5,127, , , ,
Click here to see answer by Edwin McCravy(20056)

Question 956388: The mean/ average of these three numbers is 35 there are two given to you what is the third 46,21, and ?
Click here to see answer by Alan3354(69443)

Question 956336: 2,10,12,16,17,18,19 what comes after ?
Click here to see answer by Edwin McCravy(20056)

Question 956360: How to find An and n if Sn,A1 and d is given?
Click here to see answer by Edwin McCravy(20056)

Question 954718: there are three questions
3128 3130 3130 3131 ?
3 1 2 3 2 4 5 6 ? ?
F P N ? M
Click here to see answer by Edwin McCravy(20056)

Question 952711: 1,3,25,253,?
Click here to see answer by Edwin McCravy(20056)

Question 955519: If the sum of first four terms of an arithmetic sequence is 16 and their product 105 find the terms if they all are integers ... I know that the A.s is (1,3,5,7) but how to get it
Click here to see answer by Edwin McCravy(20056)

Question 956934: Can you help me understand geometric sequences example. 5, - , 39. What would be the -? How can I find this? Thank you

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