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, ...
\(y = x + 3\) is a linear equation and \(y = x^2 + 3x\) is a quadratic equation. If the product of two numbers is zero, then one or both numbers must also be equal to zero. To solve, put each bracket ...