\(3x^2 = 48\) is an example of a quadratic equation that can be solved simply. If \((x + 1)(x + 2) = 0\), then \(x + 1 = 0\) or \(x + 2 = 0\), meaning \(x = -1\) or ...

Writing \(y = x^2 - 6x + 4 \) in completed square form ... This also gives the equation of the line of symmetry for the quadratic graph. The value of \(y\) when \(x = 3\) is -5.