Question

1. Expand.
(x - 2/x) square
using formula (a - b) square = a square — 2ab + b square
step by step

Answer 1

a=x
b=2/x
(a-b)square is a square +b square -2ab
x square +4/x square - 2×2
x Square +4/x square -4

Answer 2

$\sf{{(x - {\dfrac{2}{x}})}^{2}}$

Here, a = x, b = 2/x

$\sf{\implies (x)^2 - (2)(x)({\dfrac{2}{x}}) + ({\dfrac{2}{x}})^2}$

$\sf{\implies x^2 - 2 × {\cancel{x}} × {\dfrac{2}{{\cancel{x}}}} + {\dfrac{4}{x^2}}}$

$\sf{\implies x^2 - 4 + {\dfrac{4}{x^2}}}$

$\sf\red{\implies x^2 + {\dfrac{4}{x^2}} - 4}$