Question

44) The number of middle terms in the expansion of (2x -1/4x)^9​

Answer 1

Answer:

Given expansion term is (2x−

4

x

2

)

9

n=9= odd

middle term =(

2

9+1

)

th

+(

2

9+3

)

th

=5

th

or 6

th

term

T

5

=T

4+1

=

9

C

4

(2x)

5

(

4

−x

2

)

4

=

4!5!

9!

2

5

×x

5

(−1)

4

×

4

4

x

8

=

4×3×2×5!

9×8×7×6×5!

×

2

5

2

5

.x

13

.1

T

5

=

4

63

x

13

T

6

=T

5+1

=

9

C

5

(2x)

4

(

4

−x

2

)

5

=

4!5!

9!

×2

4

x

4

(−1)

5

4

5

x

10

=

4×3×2×5!

9×8×7×6×5!

2

4

2

10

x

14

T

6

=

32

−63

x

14