Question

The term independent of $x$ in the expansion of ${\left(x-\frac{1}{x}\right)}^4{\left(x+\frac{1}{x}\right)}^3$ is:

• A. $-3$
• B. 0
• C. 1
• D. 3

Answer 1

Answer: (B)

$\left(x-\frac{1}{x}\right){\left(x^2-\frac{1}{x^2}\right)}^3=\left(x-\frac{1}{x}\right)\left({}^3{C}_0{x}^6-{}^3{C}_1{x}^2+{}^3{C}_2{x}^{-2}-{}^3{C}_3{x}^{-6}\right)$
There is no term independent of $x$