Question

find the coefficient of x raise to 6 in the expansion of 3xsquare -1/3x raise to 9​

Answer 1

Answer:

We have (x

2

−2x)

10

=x

20

(1−

x

2

)

10

and since x

20

multiplies every term in the expansion of (1−

x

2

)

10

, we have in this expansion to seek the coefficient of the term which contains

x

4

1

Hence the required coefficient

10

C

4

(−2)

4

=

1.2.3.4

10.9.8.7

×16=3360