Question

The term independent of x in the expansion of ${(x^2-\frac{1}{x})}^6$ is

• A. -12
• B. 15
• C. 24
• D. -15

Answer 1

The correct option is B 15

$r=\frac{6\times 2}{2+1}=\frac{12}{3}=4$
$\therefore$ The term independent of x is
${}^6{C}_4(x^2{)}^{6-4}{(-\frac{1}{x})}^4{=}^6{C}_2=15$