# Answer the following: Find tenth term in the expansion of (2x2+1x)12 - Mathematics and Statistics

Sum

Find tenth term in the expansion of (2x^2 + 1/x)^12

#### Solution

We know that, the (r + 1)th term in the expansion of (a + b)n is

tr+1 = nCr, an-r br

Here a = 2x2, b = 1/x, n = 12 and for t10, r = 9

∴ tenth term in the expansion of (2x^2 + 1/x)^12

=t10 = ""^12"C"_9 (2x^2)^(12 - 9) (1/x)^9

= ""^12"C"_3 (2x^2)^3 (1/x)^9  ...[∵ nCr = nCn-r]

= (12 xx 11 xx 10)/(1 xx 2 xx 3) xx 8x^6 xx 1/x^9

= 1760/x^3

Concept: General Term in Expansion of (a + b)n
Is there an error in this question or solution?

#### APPEARS IN

Balbharati Mathematics and Statistics 2 (Arts and Science) 11th Standard Maharashtra State Board
Chapter 4 Methods of Induction and Binomial Theorem
Miscellaneous Exercise 4 | Q II. (7) | Page 85