**The principal of Square Roots**

The quadratic equation

5x^{2} + 8x – 2 = 0

is said to be in standard form. The quadratic equation

5x^{2} = 2 – 8x

Is equivalent to the preceding, but it is not in standard form.

**Quadratic Equation**

An equation of the type ax^{2} + bx + c = 0, where a, b, and c are real-number constants and a > 0, is called the standard form of a quadratic equation.

**The Principle of Square Roots**

The solutions of the equation x = d are and –.

When d > 0, the solutions are two real numbers.

When d = 0, the only solution is 0.

When d < 0, the solutions are two imaginary numbers.