Question

find the cube of За - 1/a

expansion chapter
class 9
hurry​

Answer 1

$\Huge\sf\green{Answer:-}$

$\begin{gathered}\sf (3a-\frac{1}{a})^3 \\ =(3a)^2-3(3a)^2×\frac{1}{a}+3×3a×(\frac{1}{a})^2-\frac{1}{a}^3 \\ =27a^3-27a+\frac{9}{a}-\frac{1}{a^3}\end{gathered}$