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Over Lesson 5–3 5-Minute Check 1

Over Lesson 5–3 5-Minute Check 2

Over Lesson 5–3 5-Minute Check 3

Over Lesson 5–3 5-Minute Check 4

Over Lesson 5–3 5-Minute Check 5

Then/Now Solve inequalities by using the Addition and Subtraction Properties of Inequality. Solve inequalities by multiplying or dividing by a positive or negative number.

Concept B

Start with:20 > 14 Example 1: Divide by 2:20 > Is the inequality still true?10 > 7 Example 2: Divide by -2:20 > Is the inequality still true?-10 > -7 Yes No **When you multiply/divide by a negative, reverse the direction of the symbol!

Concept C

Example 4 A Multiply or Divide by a Negative Number A. Solve –9x < –27 and check your solution. Then graph the solution on a number line. –9x<–27Write the inequality. Divide each side by –9 and reverse the symbol. x > 3Simplify.

Example 4 A Multiply or Divide by a Negative Number Answer: x > 3 To check your solution, first check the solution and then try any number greater than 3. Check #1 –9x = –27 Write the inequality with an equal sign. –27 = –27 This statement is true. –9(5) < –27 Replace x with 5. –45 < –27 This statement is true. Check #2 –9x < –27 Write the inequality. –9(3) = –27 Replace x with 3

Example 4 B Multiply or Divide by a Negative Number B. Solve and check your solution. Then graph the solution on a number line. Write the inequality. Answer: x ≤ –35 Multiply each side by –5 and reverse the symbol. x ≤ –35Simplify.

Example 4 CYP A

Example 4 CYP B A.x < 18; B.x < –2; C.x < –18; D.x > –18; B. Solve and check your solution. Then graph your solution on a number line.

End of the Lesson