Lesson 14 Student Outcomes
Students learn if-then moves using the addition and multiplication properties of inequality to solve inequalities and graph the solution sets on the number line.
Properties of Inequality
Recall the Properties of Inequality:
Addition property of inequality:
If A > B, then A + c > B + c for any real number c.
Multiplication property of inequality:
If A > B, then kA > kB for any positive real number k.
1. Find the solution set to each inequality. Express the solution in set notation and graphically on the number line.
a. 6x + 2 < 7x - 1
b. x2 + 2(x - 1) ≥ x2 + 5
2. Fergus was absent for today’s lesson and asked Mike to explain why the solution to -5x > 30 is x < -6. Mike said, “Oh! That’s easy. When you multiply by a negative, just flip the inequality.” Provide a better explanation to Fergus about why the direction of the inequality is reversed.
Rotate to landscape screen format on a mobile phone or small tablet to use the Mathway widget, a free math problem solver that answers your questions with step-by-step explanations.