Inequalities In Algebra County

Types of inequality symbols

How to read inequalities

x is greater than 5

x is greater than or equal to 5

x is less than 5

x is less than or equal to 5

4 is less than x x is greater than 4

Examples

“Mike, you cannot eat more than 3 hot dogs.” Let h = hot dogs

“I can only spend $90 on groceries today.” Let d = dollars spent

“There are more than 200 people here today.” Let p = number of people

“Every adult could have 32 teeth.” Let t = number of teeth

“I have less than 50 pennies in my bank.” Let p = number of pennies

“The national debt is more than three million dollars.” Let d=dollars in debt

Graphing them on a line graph

h is everthing except “3.”

Can we use the same methods for solving inequalities as we used for solving equations?

Yes, except for when we multiply or divide by a negative number.

What do we do when we multiply or divide by a negative number?

Switch the inequality sign.

Solving inequalities: examples Copy on your notes

-5 That’s legal. 33 That’s legal too

Then we write this in set builder notation:

+1 -4 That’s legal. That’s only legal if you switch the inequality sign

In set builder notation:

That’s only legal if you switch the inequality sign.

In set builder notation:

The End