Question

what is middle term of (x+4)⁶
​

Answer 1

Answer:

Correct option is

C

−

10

3

The middle term in the expansion of (1+αx)

n

is (

2

n

+1)

th

term.

General term in the expansion of (1+αx)

4

is 4

C

r

α

r

x

r

General term in the expansion of (1−αx)

6

is 6

C

r

α

r

x

r

The middle term in the expansion of (1+αx)

4

is (

2

4

+1)

th

=3

rd

term.

The middle term in the expansion of (1−αx)

6

is (

2

6

+1)

th

=4

th

term.

Given:4

C

2

α

2

=−6

C

3

α

3

⇒α=

6

C

3

−4

C

2

=

3×2×1

6×5×4

−

2×1

4×3

=

20

−6

=

10

−3