Look at the National 4 factorising section before continuing. When a question asks you to 'solve' a quadratic equation, this means that you are to find the roots of the quadratic. In other words ...

Equations that have more than one unknown can have an infinite number of solutions. For example, \(2x + y = 10\) could be solved by: \(x = 1\) and \(y = 8\) \(x = 2 ...