Question

The factorised form of the algebraic expression $(x^2-z^4)$ is

Answer 1

$x^2-z^4$

$=x^2-(z^2{)}^2$

$=(x+z^2)(x-z^2)$ $[\because a^2-b^2=(a+b\left)\right(a-b\left)\right]$

$=(x+z^2)(\sqrt{x}+z)(\sqrt{x}-z)$