4 1 to 4 3 OneStep Inequalities Symbols

4 -1 to 4 -3 One-Step Inequalities

Symbols l l < means “less than” > means “greater than” < means “less than or equal to” > means “greater than or equal to”

Graphing Inequalities To graph an inequality: 1. Draw a number line with “ 0” and the important number(s). 2. Put an open circle at the important number. 3. Decide if it stays open or is colored in. 4. Shade in the proper direction. Graph X < 3 0 3

Graphing Inequalities To graph an inequality: 1. Draw a number line with “ 0” and the important number(s). 2. Put an open circle at the important number. 3. Decide if it stays open or is colored in. 4. Shade in the proper direction. Graph X > 3 0 3

Is it a Solution? l Is 3 a solution of 2 x - 5 > 4? 2· 3 – 5 = 1. Is 1 > 4? No, not a solution.

Addition Property of Inequality l If a > b, then a + c > b + c for every real number a, b and c.

Subtraction Property of Inequality l If a > b, then a - c > b - c for every real number a, b and c.

How to Solve Treat inequalities just like equations. Solve: x – 2 < -1 +2 +2

How to Solve Treat inequalities just like equations. Solve: x – 2 < -1 +2 +2 x < 1 0 1

Multiplication Property of Inequality l l l If a > b, then a · c > b · c if c > 0 a · c < b · c if c < 0

The “Real” Rule l If you multiply or divide BY a negative number, then you have to switch the inequality sign.

How to Solve Treat inequalities just like equations. Solve: -2 x < -1 -2 -2

How to Solve Treat inequalities just like equations. Solve: -2 x < -1 -2 -2 x > 1/2

Today’s Assignment l l P. 202 #4 -48 multiples of 4 P. 208 #4 -44 multiples of 4 P. 215 #1 -27 odds DUE AT END OF HOUR! (even if you are not done, we will work some more on it on Monday)