Question

Factorise: ${\displaystyle 9x^2-\frac{1}{16}}$

Answer 1

${\displaystyle 9x^2-\frac{1}{16}}$

= ${\displaystyle {\left(3x\right)}^2-{\left(\frac{1}{4}\right)}^2}$

= ${\displaystyle (3x+\frac{1}{4})(3x-\frac{1}{4})}$