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and Ry's MathML Tutorial, a quick and simple reference to MathML.


What is a Quadratic Equation? 
A quadratic equation is a singlevariable equation in which the highest power on the variable is 2. The standard form is:
${\mathrm{a}x}^{2}+\mathrm{b}x+\mathrm{c}=0$
where
$\mathrm{a}$,
$\mathrm{b}$, and
$\mathrm{c}$ are real numbers and
$\mathrm{a}\ne 0$
.



Solving Quadratic Equations 
There are three methods for solving a quadratic equations:
 Factoring

Factoring is a process of changing the form of an equation from the standard form into the product of two factors:
$(\mathrm{a}x+\mathrm{b})(\mathrm{c}x+\mathrm{d})=0$
Once the equation is in this form, each factor is set equal to 0 and solved for x. This uses the ZeroProduct Property that says if the product of two factors equals zero, then at least one of the factors must equal zero.
$(\mathrm{a}x+\mathrm{b})=0$
OR
$(\mathrm{c}x+\mathrm{d})=0$
 Completing the Square

Completing the square is a process of changing the form of an equation from the standard form so that both sides are perfect squares:
${(x+\mathrm{b})}^{2}={\mathrm{c}}^{2}$
Once it’s in this form, the solutions can be found by taking the square root of both sides and solving for x.
 Quadratic Formula

The quadratic formula is:
$x=\frac{\mathrm{b}\pm \sqrt{{\mathrm{b}}^{2}4\mathrm{a}\mathrm{c}}}{2\mathrm{a}}$
I prefer this form:
$x=\frac{\mathrm{b}\pm \sqrt{\mathrm{d}}}{2\mathrm{a}}$
where
$\mathrm{d}$
is the discriminant
${\mathrm{b}}^{2}4\mathrm{a}\mathrm{c}$



Solve a Quadratic Equation 




