In a quadratic expression, the highest power of \(x\) is \(x^2\). Factorise \(x^2 + 7x + 10\). To factorise this expression, find two numbers that have a product of +10 and a sum of +7.

Using the quadratic formula is another method of solving quadratic equations that will not factorise. You will need to learn this formula, as well as understanding how to use it. Key fact The ...