Question

Find the middle term(s) in the expansion of
(3/5x^3-5/3x)^13
​

Answer 1

Answer:

∵ Given (2x/3 + 3y/2)²⁰

n = 20 ⇒ even

For even Values of n , middle term is (n/2 + 1)th

e.g., middle term = (20/2 + 1)th = 11th

∴ Here, r = 10, a = 2x/3 and b = 3y/2

Now, T₁₁ = ²⁰C₁₀ (2x/3)²⁰⁻¹⁰ (3y/2)¹⁰

T₁₁ = ²⁰C₁₀(2x/3)¹⁰(3y/2)¹⁰ =²⁰C₁₀ (xy)¹⁰