Question

Factorise:
$x^9-\frac{9}{16}$

Answer 1

$x^9-\frac{9}{16}$

$(x-y)(x+y)=x^2-y^2$

$\Rightarrow \left(\right(x^{9/2}{)}^2-{\left(\frac{3}{4}\right)}^2)$

$=(x^{9/2}-\frac{3}{4})(x^{9/2}+\frac{3}{4})$