Main Idea and New Vocabulary

Example 1: Write Inequalities

Example 2: Write Inequalities

Example 3: Write Inequalities

Example 4: Write Inequalities

Example 5: Determine the Truth of an Inequality

Example 6: Determine the Truth of an Inequality

Example 7: Graph an Inequality

Example 8: Graph an Inequality

• Write and graph inequalities.

• inequality

Write Inequalities

Write an inequality for the sentence.Johann needs less than 2 hours to paint his room.

Let r = the number of hours.

Answer: r < 2

A. c < 5

B. c > 5

C. c ≤ 5

D. c ≥ 5

Write an inequality for the sentence.More than 5 cups of popcorn are needed to make popcorn balls.

Write an inequality for the sentence.Lena walked more than 20 miles for charity.

Write Inequalities

Let w = the number of miles.

Answer: w > 20

A. d < 3

B. d > 3

C. d ≤ 3

D. d ≥ 3

Write an inequality for the sentence.Josh has less than 3 days to return his library books.

Write Inequalities

Write an inequality for the sentence.At least $30 must be spent to get a discount on the groceries.

Let g = the amount spent on groceries.

Answer: g ≥ 30

A. f < 7

B. f > 7

C. f ≤ 7

D. f ≥ 7

Write an inequality for the sentence.An aquarium can hold no more than 7 fish.

Write an inequality for the sentence.There can be at most 5 people in the car.

Write Inequalities

Let p = the number of people.

Answer: p ≤ 5

A. x > 6

B. x < 6

C. x ≥ 6

D. x ≤ 6

Write an inequality for the sentence.A plant needs at least 6 hours of sunlight.

Determine the Truth of an Inequality

State whether the inequality x – 4 < 6 is true or false for x = 0.

x – 4 < 6 Write the inequality.

– 4 < 6 Simplify.

0 – 4 < 6 Replace x with 0.?

Answer: Since –4 < 6 is true, the inequality is true for x = 0.

A. true

B. false

State whether the inequality 10 y – 3 is true or false for y = 8.

Determine the Truth of an Inequality

State whether the inequality 3x ≥ 4 is true or false for x = 1.

3x ≥ 4 Write the inequality.

3(1) ≥ 4 Replace x with 1.?

Answer: Since 3 is not greater than or equal to 4, 3 ≥ 4 is false. So, the inequality is false for x = 1.

3 ≥ 4 Simplify.

A. true

B. false

State whether the inequality 6x 5 is true or false for x = –1.

Graph an Inequality

Graph the inequality n > –1 on a number line.

Answer:

Place an open dot at –1. Then draw a line and an arrow to the right.

Graph the inequality k < –3 on a number line.

A.

B.

C.

D.

Graph an Inequality

Graph the inequality n ≤ –1 on a number line.

Answer:

Place a closed dot at –1. Then draw a line and an arrow to the left.

Graph the inequality x > 4 on a number line.

A.

B.

C.

D.