Proof Formula ABC (Another Way)

There are three methods that are often used in solving quadratic equations, namely factoring, complete perfect square, and use the formula abc (quadratic formula). In seeking to resolve quadratic equations, we usually try memfaktorkannya first. If we encounter obstacles, then we use the formula abc or complete perfect square. This time we will prove the formula abc in other ways, though the same principle, that is, change the left side will be a perfect square shape.

$ax^2 + bx + c = 0$

So that the left side will be converted into the shape of squares, the coefficients of $x^2$ should form squared. Previously we divide the equation by a, so that we gain coefficient 1 which is the simplest quadratic numbers. In proof of this, we multiply the equation with 4a, in order to obtain $4a^2$ coefficients $x^2$ .

$4a^2 x^2 + 4abx + 4ac = 0$