Lesson 3-2
Problem of the day Identify any errors in the work below: 3 x x > 23Original Equation 9 x + 5 > 23Combine like terms +5 +5Addition property of equality 9 x > 28 Combine like terms 9 9Division property of equality x > 28Simplify 9
Chloe and Charlie’s Problem Recall: Chloe and Charlie went to the pet store to buy their dog some toys. You created an inequality and solved it algebraically to come up with a solution yesterday.
Algebraic method Charlie liked solving the inequality from yesterday algebraically, so he decided to try it on this problem: -2 x – 4 > 8
Two Methods Method 1: -2 x – 4 > x > x > -6 Method 2: -2x – 4 > 8 +2x +2x -4 > 8 + 2x > 2x > x
Charlie’s Experiment DirectionsNumbersInequality Pick two different numbers 2 and 42 < 4 Multiply both numbers by 3 2(3) and 4(3) < 12 Multiply both numbers by -3 2(-3) and 4(-3) > -12 Divide both numbers by 2 2÷2 and 4÷ < 2 Divide both numbers by -2 2÷ –2 and 4÷ – > -2
Charlie’s Experiment DirectionsNumbersInequality Pick two different numbers 2 and 42 < 4 Multiply both numbers by 3 2(3) and 4(3) < 12 Multiply both numbers by -3 2(-3) and 4(-3) > -12 Divide both numbers by 2 2÷2 and 4÷ < 2 Divide both numbers by -2 2÷ –2 and 4÷ – > -2
Your turn! DirectionsNumbersInequality Pick two different numbers Multiply both numbers by 3 Multiply both numbers by -3 Divide both numbers by 2 Divide both numbers by -2 As you create your table think about: 1) Did you notice the same thing happening with your table and Charlie’s table? 2) Can we create a rule about what happens to the inequalities?
Homework