# How to Find the Directrix & Focus in Algebra?

A parabola is defined as the set of points equidistant from a given point, the focus, and a straight line, called the directrix. A parabola is also defined by the set of points on a Cartesian plane...
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http://www.ehow.com/how_8175222_directrix-focus-algebra.html

## How to Find Perimeters in Pre-Algebra?

The perimeter of a shape is merely the distance around the shape's exterior. Think of perimeter as the fence or wall that goes completely around a property. A farmer requires a perimeter total to k...
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http://www.ehow.com/how_8273057_perimeters-prealgebra.html

## How to Find Probability in Pre-Algebra?

Probability refers to the likelihood that something will happen. In math, probability refers to the number of ways that the desired outcome could occur divided by the total number of possible outco...
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http://www.ehow.com/how_8288492_probability-prealgebra.html

## How to Find X in an Algebra Question?

Algebra is a type of mathematics that introduces the concept of variables representing numbers. "X" is one such variable used in algebraic equations. You can find "x" or solve the equation for "x" ...
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http://www.ehow.com/how_7889204_algebra-question.html

## How to Find the Area in Pre-Algebra?

Students younger than fifth or sixth grade can struggle with the idea of substituting letters for numbers, but this difficulty shouldn't put geometry out of their reach. Simply avoid talking about ...
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http://www.ehow.com/how_8229512_area-prealgebra.html