1.5 - Linear Equations and Inequalities

1.5 - Linear Equations and Inequalities

Author: Kyle Webb

In Algebra, you learned about linear equations and inequalities.  Specifically, we can write the equation of a line if we have certain information:  two points, a point and the slope, or the y-intercept and the slope.  We have also learned three forms to use to write the equation of a line and when to use each form.  We will review these forms of equations of lines as well as look at linear inequalities in this section.  

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Point-Slope, Slope Intercept and Standard Forms

Parallel and Perpendicular Lines

How do you know if two lines are parallel?

Their slopes are the same!


How do you know if two lines are perpendicular?

When you multiply their slopes, you get -1

or The slopes are multiplicative inverses

or The perpendicular slope is the negative reciprocal



An Introduction To Solving Linear Inequalities

Using Interval Notation to Express Inequalities

Graphing Linear Inequalities

Solving Linear Compound Inequalities