Find the roots of the following equation x^2 + 6x + 5 = 0

There are a few ways to do this, firstly you notice that there is no coefficient in front of the x^2. This means you can factorise it with relative ease, by finding numbers that add to give 5 but multiply to give 6. In this example the numbers are 3 and 2. Therefore it factorises into (x + 3)(x + 2) = 0. You've done the hard part, all you need to do now is say what the roots are, which is x = -2 and x = -3. If you sub these into your equation you will get the answer 0. You can do this question a number of different ways tho, as factorising like this isn't always so easy. You can use the method of completing the square or use the quadratic formulae. Both of these methods I can explain during the interview.