Introduction to Inequalities

Introduction to Inequalities

6-305

Have we seen these signs before?

 $<,\ >,\ \le,\ \ge$  

These are inequality signs

 $2<\ 6\ means\ 2\ is\ LESS\ than\ 6$  

 $6>2\ means\ GREATER\ \left(more\right)\ than\ 2$  

The "mouth" always faces the bigger side!

Multiple Choice

Which inequality should go in the middle?

 $5\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 4$  

• >

• <

Multiple Choice

Which inequality should go in the middle?

 $3\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 4$  

• >

• <

What might be the difference between

 $<\ and\ >\ compared\ to\ \le\ and\ge?$  

If the inequality sign has a line under it, it means "or equal to"

 $2\le6\ means\ 2\ is\ less\ than\ or\ equal\ to\ 6$   $6\ge2\ means\ 6\ is\ greater\ than\ or\ equal\ to\ 2$  

 $<is\ less\ than$  
 $\le is\ less\ than\ or\ equal\ to$  


 $>is\ greater\ than$  

 $\ge\ is\ greater\ than\ or\ equal\ to$  

*Remember the mouth always face the bigger side*

Multiple Choice

 $x\ \le\ 6$  

How would you read this?

• x is LESS than 6

• x is LESS than OR EQUAL 6

• x is GREATER than 6

• x is GREATER than OR EQUAL to 6

If x must be LESS THAN or EQUAL to 6? What could x equal?

X could equal 6 OR any number less than 6.

It could equal 6 or 5 or 4 or 3 or 2 or 1 or 0

With an inequality, there is always MORE THAN 1 answer!

Multiple Choice

 $r\ \ge\ 2$  

Which of these numbers could r NOT equal?

• 1

• 2

• 3

• 999