Question

x^5in the expension of [2clx^2-30x]^10 coefficient​

Answer 1

Answer:

T

r+1

=

10

C

r

3

10−r

(−b)

r

⋅x

20−2r−3r

∴20−5r=5 or -15

∴r=3 or r=7

∴ Coeff. of x

5

is −9720b

3

and that of x

−15

is −

27

40

b

7