Day 1- 2 Combined

Algebra I

Unit 2 Day 1 & 2

Unit: Analyzing Linear Inequalities

Do Now

Identify the slope and y-intercept for equation of the line on the graph below

Do Now

Do Now

Learning Target

I can graph two-variable linear inequalities in slope-intercept and standard form.

Direct Instruction

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Key Vocabulary for Linear Inequalities Symbols

Direct Instruction

Key Vocabulary for Linear Inequalities in Two Variables

Direct Instruction

How do you graph an inequality in two variables in slope-intercept form?

Scenario: You are playing the game “Guess My Number.” Here is the clue: The second number ,y, is more than twice the first number. The inequality y > 2x represents this scenario.

Step 2: Graph the "y=" line (make it a solid line for y≤ or y≥, and a dashed line for y< or y>)

y > 2x

Step 1: Make sure your inequality is in slope intercept form. (y=mx+b)

y = 2x

Direct Instruction

How do you graph an inequality in two variables in slope-intercept form?

Reveal

Test Point: (5,4)

Step 3: Substitute a test point that’s not on the boundary line into the inequality to determine the appropriate half plane to shade.

• If the test point makes the inequality true, shade the half plane where the test point is located.
• If the test point makes the inequality false, shade the half plane that does not include the test point.

y > 2x

Direct Instruction

How do you graph an inequality in two variables in slope-intercept form?

(5,4)

Direct Instruction

Key Vocabulary for Linear Inequalities in Two Variables

Direct Instruction

How do you write an inequality in two variables in standard from?

Scenario: A store sells hardback books at $5 each and paperback books at $2 each. Write an inequality that models this situation if Maria plans to spend less than or equal to $39 at the store.

5x + 2y 39

Direct Instruction

How do you graph an inequality in two variables in standard from?

Guided Practice

The Science Club sells T-shirts and key chains to raise money. Write and graph the linear inequality that represents the combinations of T-shirts and key chains could they sell to meet or exceed their goal?

Reflect

How can I graph a two-variable inequality in slope-intercept form and standard form? How can I test if an order pair is a solution to a two-variable inequality?