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 332881: find the first five terms of a1=3, aN=aN-1+2(n-2), n>or=2
Click here to see answer by Edwin McCravy(20056)

Question 335383: I have a triangle of dots progressing in size. The first triangle has one dot, the second triangle has three dots, the third triangle has nine dots, ect. I need help with the formula when it asks how many dots the "nth" triangle has.
Click here to see answer by Edwin McCravy(20056)

Question 335387: What is the series with summation notation of the following fractions: thank you so much!
Click here to see answer by Edwin McCravy(20056)

Question 335634: Alfred is practicing typing. The first time he tested himself, he could type 23 words per minute. After practicing for a week, he could type 26 words per minute. After two weeks he could type 29 words per minute. Based on this pattern, predict how fast Alfred will be able to type after 4 weeks of practice
Click here to see answer by stanbon(75887)

Question 336210: An auditorium has 20 rows of seats.These are 20 seats in the first row,21 in the second row and 22 in the third row and so on.how many seats are there in all rows?
Click here to see answer by galactus(183)

Question 336304: a G.P has a first term of a, a common ratio of r and its 6th term is 768. another G.P has a first term of a, a common ratio of 6r and its 3rd term is 3456. evaluate a and r.
Click here to see answer by galactus(183)

Question 336393: find a formula for 43, 41, 39, 37, 35
Click here to see answer by user_dude2008(1862)

Question 336429: I need to find the 100th term, for the sequence 2,6,12,20
Click here to see answer by Edwin McCravy(20056)

Question 336461: fill in the blank with one of the digits from 1 through 9 (using each digit only once) to make a true statement. using the following functions / then x then+ then x then x then / then + then x that = 100 (___ / ___ x ___ + ___ x ___ x ___ / ___ + ___ x ___ =100)

Click here to see answer by Edwin McCravy(20056)

Question 336658: what is the sequence of 6, 12, 9, 18, 15?
Click here to see answer by Edwin McCravy(20056)

Question 336706: find the sum of each of the following infinite seies.if a series does not have a sum write no sum as the answer
1) 1/2+1+2+4
2)9-3+1-1/3+1/9
Click here to see answer by Fombitz(32388)

Question 336724: find the missing numbers to complete the pattern
1,2,_, _, _, 32
Click here to see answer by Fombitz(32388)

Question 336724: find the missing numbers to complete the pattern
1,2,_, _, _, 32
Click here to see answer by jim_thompson5910(35256)

Question 336715: a. 1, 3, 5, 7, 9
b. 0, 50, 100, 150, 200
c. 3, 6, 12, 24, 48
d. 10, 100, 1,000, 10,000, 100,000
e. 9, 13, 17, 21, 25, 29
f. 1, 8, 27, 64, 125
Find the 100th term and the nth term for each of the
sequences in exercise 2.
Click here to see answer by Edwin McCravy(20056)

Question 337512: Can you help me find the following 3 numbers:
1, 5, 14, 30, 55 ___ ___ ___?
Click here to see answer by Fombitz(32388)

Question 337511: Can you help me find the following next 3 numbers:
1, 1, 2, 3, 5, ___ ____ ___ ?
Click here to see answer by solver91311(24713)

Question 337388: For the pattern shown below, describe a rule for finding the next term. Then use your rule to write the next 3 terms....

-2, -8/5, -6/5, -4/5,... the next one is -2/5 I'm not sure about the next two. I'm thinking the next one is -1 but not sure at all. Thank you.
Click here to see answer by mananth(16946)

Question 338482: write an equation for the following sequence:
0, 10, 15, 17.5 18.75

Click here to see answer by fractalier(6550)

Question 338550: Z W Y X
The sequence above may be changed in either of two ways. Either two adjacent letters may be interchanged or the entire sequence may be reversed. What is the least number of such changes needed to put the letters into alphabetical order left to right?
A. 2 B. 3 C. 4 D. 5 E. 6
Click here to see answer by Edwin McCravy(20056)

Question 338686: What is the 30th term in the sequence 14,19,24,29?

What is the 69th term in the sequence 13,19,25,31?
Click here to see answer by nerdybill(7384)

Question 338871: 1,1,2,3,5,8,13,21 what are the three next number?
Click here to see answer by Jk22(389)

Question 338816: -2, 2, 18, 52, � If the rth term in the sequence given is defined as r^3-3r then what is the next term in the sequence?
Click here to see answer by Fombitz(32388)

Question 339231: Find the nth term formula for the given arithmetic sequence; 9,7,5,3....
Click here to see answer by alanc(27)

Question 339712: trying to re-learn algebra, cannot figure out how the answer is 35. Would appreciate your help in explaining/showing the breakdown of the problem.
8-9[(-39)/(-13)+7(-2)-(-2)^3
here's what i did:
8-9[(-39)/(-13)+7(-2)-(-8)]=8-9[3+(-14)-(-8)]
=8-9[-11-(-8)]
=8-9[-19]
=8-171
=-163
Click here to see answer by Edwin McCravy(20056)

Question 339816: the sum of two consecutive number is 3.5. find the number
Click here to see answer by stanbon(75887)

Question 339816: the sum of two consecutive number is 3.5. find the number
Click here to see answer by jrfrunner(365)

Question 339877: the bob of a pendulum swings through an arc of 24cm long on its first swing. if each succesive swing is apporximately 5/6ths the length of the preceding swing, use an infinite geometric series to approximate the total distance the bob travels
Click here to see answer by stanbon(75887)

Question 339881: in the american version of roulette, a ball is spun around a wheel and has an equal chance of landing in any one of 38 slots numbered 0,00, 1,2....,36 shown in the figure is a standard betting layout for roulette, where the color of the oval corresponds to the color of the slot on the wheel. find the probability that the ball lands in A) in a black slot and B) in a black slot twice in succession
Click here to see answer by edjones(8007)

Question 340070: What is the equation for this sequence?
1, 4, 9, 17, 29,...
I tried n(n-1) + n where n is the nth term, and that only works for the first three terms.
Click here to see answer by Edwin McCravy(20056)

Question 340227: What is the next term in the sequence...3692, 738, 584, 232...?
Click here to see answer by stanbon(75887)

Question 340326: I can't understand this sequence an+1= an + 3 a1=1
the result would be 1 4 7 10 but how does it work
Click here to see answer by Fombitz(32388)

Question 340667: If y/x=4 and x+y=5, then x is: Please show steps and solution.
Click here to see answer by rfer(16322)

Question 340699: One number is two more than a certain number n. Another number is five less than n. The sum of the three numbers is _? Using the given information and variables, create an expression that will correctly solve the question.
Click here to see answer by mananth(16946)

Question 340806: 4,-1,5,3,-2 4,-1,5,3,-2 4,-1,5,3,-2.....
find the sum of the first 89 terms of the sequence... I don't need this solved but can you show me an example please
Click here to see answer by Theo(13342)

Question 340937: Solve the equation for x. If necessary, round your answer to two decimal places.
5^x= 24
Click here to see answer by nerdybill(7384)

Question 341259: whats the next 3 numbers in the sequence..
4, 7, 15, 28, 46 ...
Click here to see answer by texttutoring(324)

Question 341352: I need help with this question;
an = 1/2n + 1/2
Click here to see answer by Fombitz(32388)

Question 341734: 1, 4, 7, 10, ... What is the 100th number in this sequence?
Click here to see answer by Edwin McCravy(20056)

Question 341998: The sum of three consecutive intergers is 90.
a. Find the three numbers by letting x represent the first integer.
b. Find the three numbers by letting x represent the second number.
Click here to see answer by Alan3354(69443)

Question 341967: solve the equation for x in terms of the other variables
b(x-d)=c(x+d) and show work.
So far, I have distributed to be BX-BD=CX+CD
Then, I got all X's on one side to be BX-CX=BD+CD
Where do i go from here? I know that it has something to do with factoring yet I am still stumped.
Click here to see answer by ankor@dixie-net.com(22740)

Question 342107: How do you go about finding a pattern in a sequence of numbers? i just keep trying out different numbers but i just sit there for hours and some times i still don't see a pattern. Is there a process for finding a pattern?
Click here to see answer by stanbon(75887)

Question 342104: what are the patterns in these two sequences:
1/8, 2/7, 1/2, 4/5
and
360, 180, 120, 90
Click here to see answer by checkley77(12844)

Question 342181: The sum of the third and fourth terms in a sequence of consecutive integers is 47. What is the sum of the first five terms of the sequence?
I have been trying to figure out this problem for hours! I am a new highschool freshman and was thinking that is was 21 22 23 24 and 25 but i honestly have no clue.
Click here to see answer by scott8148(6628)

Question 342936: Snookers lumber can convert logs into either lumber or plywood. In a given day, the mill turns out twice as many units of plywood as lumber. It makes a profit of $20 on a unit of lumber and $40 on a unit of plywood. How many of each unit must be produced and sold in order to make a profit of $10,100
Click here to see answer by josmiceli(19441)

Question 343404: What is the next term in the following sequence?
21, 22, 24, 25, 29, 30, 36, 37...
Click here to see answer by Jk22(389)

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