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 1056127: The third term of an a.p is 9,while the 11th term is -7,find the first five terms of the a.p
Click here to see answer by josgarithmetic(39618)

Question 1054536: what is the formula for sequences {0.2,0.22,0.222,0.2222�}

Click here to see answer by Edwin McCravy(20056)

Question 1056501: The sum of the first two terms of an arithmetic progression containing four terms is 110, and
the sum of the last two terms is 190.
a. Determine the first term.
b. Obtain the common difference.
c. List all the four terms of the series
Click here to see answer by josgarithmetic(39618)

Question 1056567: Use any suitable method to find the sum of
63+68+73+...+103+108
Click here to see answer by ikleyn(52788)

Question 1056567: Use any suitable method to find the sum of
63+68+73+...+103+108
Click here to see answer by MathTherapy(10552)

Question 1054759: solve using the substitution method
problem 2x-y-z=15
4x+5y+2z=10
-x-4y+3z=-20
problem 4x+y+5z=-4
-3x+2y+4z=10
x-y-2z=-2
problem x+3y-z=12
2x+4y-2z=6
-x-2y+z=-6
Click here to see answer by Edwin McCravy(20056)

Question 1056796: 1) A second term of a geometric sequence is 24, the fifth term is 81. find the 7th term.
2) find the 5th term of sequence -3,2,7.......
Click here to see answer by josgarithmetic(39618)

Question 1057029: Proof that the sums of the first N Square Numbers is given by
=[n(n+1)(2n+1)]/6
Click here to see answer by stanbon(75887)

Question 1057042: In a certain lottery the player chooses 6 numbers from the numbers 1 through 38. In how many ways can the 6 numbers be chosen?
Click here to see answer by jorel555(1290)

Question 1057041: How many 9-digit numbers are there if the first digit and the third digit cannot be a 0 or a 1?
Click here to see answer by Alan3354(69443)

Question 1057049: A small combination lock on a suitcase has 5 wheels, each labeled with the 10 digits 0 to 9. how many 5-digit combinations are possible if digits can be repeated? (hint: the word combination is a misnomer. Lock combinations are not mathematical combinations because the arrangement of the numbers is important.) Please help, this is confusing
Click here to see answer by ikleyn(52788)

Question 1057078: A student dance committee is to be formed consisting of 2 boys and 4 girls. If the membership is to be chosen from 7 boys and 6 girls, how many different committees are possible?
Click here to see answer by stanbon(75887)

Question 1057138: What is the formula for the sum of the the squares of the nth natural number?
Click here to see answer by solve_for_x(190)

Question 1057138: What is the formula for the sum of the the squares of the nth natural number?
Click here to see answer by addingup(3677)

Question 1057138: What is the formula for the sum of the the squares of the nth natural number?
Click here to see answer by ikleyn(52788)

Question 1057149: If An=1/n(n+1) for all positive integer n, What is the sum of the first 100 elements of An?
Click here to see answer by ikleyn(52788)

Question 1057154: 1,4,27,16 and 125..
Click here to see answer by ikleyn(52788)

Question 1057533: 48,41,34,27,20 which number is next
Click here to see answer by Cromlix(4381)

Question 1057533: 48,41,34,27,20 which number is next
Click here to see answer by Fombitz(32388)

Question 1057553: The number of different cars sold in some country rose from 208 in 1997 to 275 in 2007. Find the percent increase. Round to the nearest whole percent
Click here to see answer by Cromlix(4381)

Question 1057596: Write the first four terms of the sequence whose general term is given
An=4n-3
Click here to see answer by Boreal(15235)

Question 1057735: Problem
The sum of 6 consecutive integers is 519.
What is the third number in this sequence?
Click here to see answer by rothauserc(4718)

Question 1057946: Simplify 0.2�0.2�0.02�0.02/0.0404
Click here to see answer by rfer(16322)

Question 1057961: Find the sum of all odd integers between 28 and 232.
Click here to see answer by Alan3354(69443)

Question 1057961: Find the sum of all odd integers between 28 and 232.
Click here to see answer by josmiceli(19441)

Question 1057962: The sequence s, t, (2t - s), (3t - 2s) ... forms an Arithmetic sequence. True or false
The sequence 1/3, 1/4, 1/6, 1/12, ... is neither Arithmetic nor Geometric True or false
Click here to see answer by ikleyn(52788)

Question 1057963: Find the sum of the first ten terms of the sequence 128, -64, 32, -16, �.
Click here to see answer by jorel555(1290)

Question 1057699: how do i substitute r which is 4/� in �(�+ar+ar^2)

Click here to see answer by ikleyn(52788)

Question 1058223: When solving a line of numbers separated by +, -,x,
division sign, if there are no parentheses, do you solve the equation in the order that the signs appear ??
Click here to see answer by ikleyn(52788)

Question 1058352: if three persons are 15 kg
a cock and a person is 20 kg
a dog minus a cock is 40 kg
what will b the weight of a person a cock and a dog
Click here to see answer by josmiceli(19441)

Question 1057206: Find the next number in the following series 3/4,1,9/8,6/5,5/4,9/7,?
Click here to see answer by Edwin McCravy(20056)

Question 1058471: What is the numbers of terms and the common difference if the first term is -13 and the last term is 99. And the sum of the progression is 1419
Click here to see answer by KMST(5328)

Question 1058585: How do I turn this into recursive rule?
This is all the problem gives me.
Plz help, and thank you!
An = -2 + 6n
Click here to see answer by solve_for_x(190)

Question 1058547: I need help with my sequence of numbers, I have a set: 1280,5080,9080,10080,17080,21080,29080,41080,45080,57080. I want to know 12 numbers that follow 57080. I just can't figure out the pattern(besides it ending in 80)
Click here to see answer by Edwin McCravy(20056)

Question 1058638: What's the next number in the series?
4, 12, 13, 15, 14, 10, 11, 9 ...

Click here to see answer by Alan3354(69443)

Question 1058638: What's the next number in the series?
4, 12, 13, 15, 14, 10, 11, 9 ...

Click here to see answer by math_helper(2461)

Question 1058638: What's the next number in the series?
4, 12, 13, 15, 14, 10, 11, 9 ...

Click here to see answer by rothauserc(4718)

Question 1058638: What's the next number in the series?
4, 12, 13, 15, 14, 10, 11, 9 ...

Click here to see answer by Edwin McCravy(20056)

Question 1058628: What is the next number to complete the sequence 8, 4, 2, 7, 5, 2, 7?
Either 4, 5, 7 or 2?
Click here to see answer by ikleyn(52788)

Question 1058628: What is the next number to complete the sequence 8, 4, 2, 7, 5, 2, 7?
Either 4, 5, 7 or 2?
Click here to see answer by t_n_v(1)

Question 1058987: After a long period of heavy rain, water seeps into an underground cave. After a day there are 5000 liters of water in the cave. The next day 4000 liters of water seeps into the cave. The day after, 3200 liters of water seeps into the cave, and so on.
A) How much water seeps into the cave on the 5th day?
B) How much water in total has seeped into the cave after 5 days?
C) How long before 20,000 liters of water in total have seeped into the cave?
D) if the water keeps seeping into the cave indefinitely, and none is lost, how much water will be in the cave eventually?

Click here to see answer by Boreal(15235)

Question 1059131: Find the first term and the common difference
6,8,10,12....
1/5,-1/6,-2/3,-7/6,...
Click here to see answer by ikleyn(52788)

Question 1059350: 10 sigma 3 = (3n + 2)
Calculate the first and last terms
Click here to see answer by ikleyn(52788)

Question 1059348: List the ﬁrst 10 terms of each of these sequences
the sequence whose nth term is the sum of the ﬁrst n positive integers

Click here to see answer by ikleyn(52788)

Question 1059428: The first three terms of a geometric sequence are as follows.
-10,40,-160

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