Question

The sum of the coefficients of $(6\,a-5\,b)^n$, where $n$ is a positive integer, is

• A. $1$
• B. $-1$
• C. $2^n$
• D. $2^n-1$

Answer 1

Answer: (A)

$1$

Answer 2

For the sum of the coefficients in the expansion of $(6 a-5 b)^{n}$, put $a=b=1$
$\therefore$ Sum of the coefficients $=(6-5)^{n}$
$=1^{n}=1$