To factorise this expression, identify the HCF of \(6x\)and 9, which is 3. The HCF of \(6x+9\) is 3. Write 3 in front of the bracket: ...

The difference of two squares can be factorised into brackets using the method above for factorising quadratics. Factorise \(x^2 - 4\). Quadratics can be factorised into the form \((x + a)(x + b)\).

THIS book gives a connected account of the author's researches on the algebraic side of the theory of differential equations and forms a welcome addition to the literature of the subject ...