Question

Find the specified nth term in the expansion of the binomial. (Write the expansion in descending powers of x.)
(x + 5y)^10, n = 4

A. 210x^6y^4
B. 15,000x^7y^3
C. 210x^6y^4
D. 9,765,625y^10
E. 5040x^6y^4

Answer 1

n=10? I believe???

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Answer 2

nevermind... term in the expansion

Answer 3

which is a different variable rth term of expansion

Answer 4

I guess I understand how to write it all out just not how to simplify it correctly to get a condensed answer like the ones they provide

Answer 5

http://www.wtamu.edu/academic/anns/mps/math/mathlab/col_algebra/col_alg_tut54_bi_theor.htm Look at example 8... if you have problems I'll do it out for you

Answer 6

pascals triangle

Answer 7

Ha ha I'm on that site right now trying to work it out lol Does it matter though if it's rth term or nth term?

Answer 8

doesn't matter coz thats just a variable

Answer 9

1
1,1
1,2,1
1,3,3,1
1,4,6,4,1
1,5,10,10,5,1
1,6,15,20,15,6,1
1,7,21,35,35,21,7,1
1,8,28,56,70,56,28,8,1
1,9,36,84,126,126,84,36,9,1

1,10,45,120,210, ....

Answer 10

well if you are following the site, the rth term is 4, the nth term is 10

Answer 11

120 (x^7) (y^3)

Answer 12

answer is b though

Answer 13

120 (x^7) ((5y)^3)

Answer 14

120.125 x^7 y^3

15000 x^7 y^3

Answer 15

BBBBBBBBBB

Answer 16

\[{10 \choose 4 }=210\]
4th term is
\[210 x^6 (5y)^4\]

Answer 17

of course i could be wrong. the 'n=4' is not clear.

Answer 18

lol..... im prolly wrong :)

Answer 19

wow ok the answer I got isn't even close to any of these.... I got 100800x^7125y^3....not quite sure what id id wrong

Answer 20

the 4th term is 120 x^7 y^3 as a standard... tehn you have to account for the coeefs in the original problem....namely the +5 attached to the y

Answer 21

120 x^7 (5y)^3

Answer 22

120.125 x^7 y^3

15000 x^7 y^3 :)

Answer 23

oh ok makes sense ok Can I try another one on my own and have you check it?

Answer 24

sure; but you can check it with pascals triangle; i posted that first to like half the 10th spot ;)

Answer 25

ok :)

Answer 26

ok the problem is:


Find the specified nth term in the expansion of the binomial. (Write the expansion in descending powers of x.)

(x - 2y)^12, n = 6

I got 760x^7y^5
which is definitly not one of my answer choices....

Answer 27

at 6 eh

12 11 10 9 8 7

x^6 y^6 is gonne be the variable answers

Answer 28

you got any with ony an x^6 y^6 as an asnswer?

Answer 29

oh it's cause I used the 12 instead of the six let me try it again....

Answer 30

ack..you were right with the x and y lol...i lost count :)

Answer 31

x^7 y^5 is the 6th term

Answer 32

oh ok so I was right now....idk how I got the 760.... cause that's nowhere close to their choices

Answer 33

lol..... which choice has the right x and y parts?

Answer 34

narrow it down if its multiple choice ;)

Answer 35

- 25,344, but that just doesn't seem right to me oh well I guess

Answer 36

well lets play detective shall we :)

is the - part correct?

-2^5 = a negative right? so i believe the negative is right...

if its got the right x and y parts, then its a sure shot

Answer 37

ok well thank you very much!

Answer 38

Do you know the binomial theorem?! It's quite easy to do it using this theorem.

Answer 39

learning it I think i just have to keep practicing using cause I get numbers mixed up and stuff

Answer 40

I see.

Answer 41

ya it's weird I can find the x and y parts but the number before I somehow lkeep messing up