Linear Inequalities

An inequality has the same characteristics as an equation except that in the place of the equal sign , there is an inequality sign.

Inequality signs !

1. < '' is less than'' 2. > '' is greater than''

A tip : One can add or subtract the same number, positive or negative on both sides of the eauality without changing the inequality sign !

This is a mistake a lot students make like me.


* NOTE THIS !

1. When one multiply or divide both sides of the inequality by the same positive number, the inequality remains unchanged

2. HOWEVER! When one multiply or divide both sides of the inequality by the same NEGATIVE number, the inequality sign is reversed!


An example of a question involving number line .

Question : solve the inequalities 2x + 5 > 11 and 5x-7< 18

Note than students should solve both separately then combine on the number line to reduce mistakes.
Tip : stretching the individual solutions on a number line will help one to visualize the solution for simultaneous linear equations.