Question

use suitable identity to find [xsquare+5/2][xsquare-5/2]

Answer 1

(x²+5/2)(x²-5/2)=(x²)²-(5/2)²
=x⁴-25/4
(a+b)(a-b)=a²-b²
hope this helps you.....

Answer 2

$( {x}^{2} + \frac{5}{2} )( {x}^{2} - \frac{5}{2} ) \\ \\ \bf \: we \: can \: solve \: it \: using \: the \: identity \\ \\ (x + y)(x - y) = {x}^{2} - {y}^{2} \\ \\ = {( {x}^{2}) }^{2} - {( \frac{5}{2} )}^{2} \\ \\ = \bf \: {x}^{4} - \frac{ 25 }{4} \: \: or \: \: \frac{ {4x}^{4} - 25}{4}$

If any doubt, please ask ;)