x^2+5x+6=0 When solving quadratic equations our goal is to revert back into the form (x+a)(x+b) from the form ax^2+bx+c Thus we need to have a method when completing this: A good method in this case is that we need to find two numbers a&b When expanding (x+a)(x+b) one term that is there is ab. Then we know that 6 must be the form of ab. So we need to find numbers that make 6. Hence its either 3x2, or 6x1 Then also when added or can be substracted in respect of a minus, together needs to make 5. Hence its 3x2. Graphically the way I would teach it is using the M&A Method Further Learning: We can use the quadratic formula to solve the equation