Question

Solve this problem of binomial theorem :
find the greatest term in the expansion of :
\[\huge{(7-3x)^8}\] when x = 7

Answer 1

Why don't you try it by plugging x with 7?

\( \color{Black}{\Rightarrow (7 - 3(7))^8}\)

\( \color{Black}{\Rightarrow (7 - 21)^8}\)

Now use the binomial theorem.

Well, to be honest, I yet have no idea what x = 7 means right there.

Answer 2

Well.. you can use this formula..or derive the whole thing but will take long
\[\frac{n-r+1}{r} *\frac{b}{a} *x\]

Answer 3

@ParthKohli this seems to be easy but is not that too ..

@Mimi_x3 that is why i am fed up wait let me post what i got

Answer 4

it will take 1-2 minute just wait

Answer 5

Please check the question once again

Answer 6

there is some problem in question

Answer 7

sorry

Answer 8

This is what i did .. I am very sorry ..net was connecting and then disconnecting sorry

Answer 9

@Mimi_x3 , @k.rajabhishek @ParthKohli

Answer 10

@mathslover : please check it is -3x not 3x in the question
and u had taken 3x while answering the question

Answer 11

Oh ! yes so i am going to modify my answer but will that also work ? @k.rajabhishek

Answer 12

@lalaly @ganeshie8 any help from u ?

Answer 13

@ mathslover : if the question is (7+3x)^8 then your method of solving question is right

Answer 14

ok let us take (7+3x)^8

Answer 15

then i am right ! so what next ?

Answer 16

since r is less than equal to 27/4 i.e 6.75 : therefore the integral value of r is 6
Hence 7th term is greatest

Answer 17

but how u calculated that integral value and how to do that ?

Answer 18

since the value of r is less than 6.75 therefore the integral value which comes first and lies before 6.75 is 6