Question

Binomial:

Answer 1

\[(2-5x)^6 (1+x/)^10 \]

Answer 2

its ^10.

Answer 3

what do you want to do, simplify?

Answer 4

Find the coefficient of x in the expansion

Answer 5

http://www.xtremepapers.me/CIE/Cambridge%20O%20Levels/4037%20-%20Additional%20Mathematics/4037_w10_qp_12.pdf

Answer 6

plz chk q6 b.

Answer 7

okay

Answer 8

its answer:
http://www.xtremepapers.me/CIE/Cambridge%20O%20Levels/4037%20-%20Additional%20Mathematics/4037_w10_ms_12.pdf

Answer 9

i have no clue

Answer 10

some how we need to expand with out really expanding it because thats to long to do
like we can find the coefficient of x in 5x^2-2x+4
the coefficient of x is -2
so we got to see if there is some kind of trick we can do to finding the coefficient in your expansion

Answer 11

no, but there must b a way!

i mean its an O'level ques.
I hav my cambridge ppr tmmrw, & im badly stuckk. :/

Answer 12

have you ever seen a problem like this one?
can i find an example somewhere?

Answer 13

umm, my scanner isnt working now othrwise i should hav scannd & sndd u the example. Its in my book,

Answer 14

is it too long to type in latex form?

Answer 15

or you don't even have to use latex
im sure i can make it out

Answer 16

:/

Answer 17

thnks for your Help.. =)

Answer 18

maybe we can do something with pascals's triangle one sec

Answer 19

Yeah, its the same thing.

Answer 20

the coefficient of the x term?

Answer 21

Yes.
the ques says:
Find the coefficient of x in the expansion

Answer 22

if that is all you want it is -320

Answer 23

satellite how did you do it so fast

Answer 24

Wow!

Answer 25

no, not wow.

Answer 26

is that right khan?

Answer 27

its somrthing
–960 + 320
= –640

Answer 28

this is the final answer

Answer 29

satelite??? HOWW?

Answer 30

the way im doing it is too long lol

Answer 31

do u want the highest index of the variable????

Answer 32

ok here goes.

Answer 33

\[(2-5x)^6 = 2^6 + stuff\]

Answer 34

if yes then highest index will b 16

Answer 35

and the x term in
\[(1+x)^{10}=10x\]

Answer 36

so one way to get an x is
\[2^6\times 10x=640x\]

Answer 37

the other way to get an x term is
\[(1+x)^{10}=1+stuff\]

Answer 38

and the x term in
\[(2-5x)^6\] is
\[6\times (-5x)^2\times 2^5\]

Answer 39

binomial explansion yes? it is \[6ab^5\] where a = -5x and b = 2

Answer 40

(-5x)^1*?

Answer 41

i just put that in there to make it match up. the term is
\[6ab^5\]

Answer 42

so we get \[6\times (-5) \times 2^5=-960\]\]

Answer 43

combining like terms, as we say in the math biz, gives
\[-960x+640x=-320x\]

Answer 44

k?

Answer 45

oops yes myininaya i made a typo. it should be
\[6(-5x)^12^5\] sorry

Answer 46

it is the x term so certainly not
\[(-5x)^2\] like i wrote. answer is right tho

Answer 47

:)

Answer 48

good thing they only asked for the x term. imagine what you would have to do if you wanted the x^2 term!

Answer 49

i like to here you made a mistake
it makes me feel good
lol

Answer 50

answer was right, so that only counts as a typo!

Answer 51

no im putting this down in my scorebook verus you
i think i might be winning now

Answer 52

gj satellite on the problem

Answer 53

no! answer right = typo. answer wrong = mistake! thnx
btw you have way more fans than i do

Answer 54

you have more medals
i guess they just pretend to like me

Answer 55

now i think it is beer o'clock.

Answer 56

later

Answer 57

thnks Guys! =)