2018-10-29

Solving Inequalities: Day 1

Starter:

  1. Find your new seat. Use the chart on the north wall, and make sure the number on your chair matches your number on the chart.
  2. In your team, explain how to graph -6+-12 on a number line.
  3. In your team, discuss why
    (-6)(-8)=(-1)(-1)(6)(8).
  4. In your team, discuss how to simplify
    3(x+6)-(4x+18).
What You Ought to Know about Inequalities:

  1. Solving inequalities is the same as solving equations unless the coefficient is negative, in which case the inequality symbol needs to be reversed.
  2. Properties of operations, including their inverses, can be used to isolate and define independent variables.
    *"Inverse" means the same as "reverse," so the inverse of multiplication is division, the inverse of subtraction is addition, etc.
  3. Coefficients show multiples of an independent variable.
  4. Constants show invariable numbers: they do not change because they are not variable, and they are not related to variables.
    *"Variable" means it can change.
  5. Independent variables are usually unknown or changeable values.
  6. Dependent variables are defined by operations with constants, coefficients, and independent variables.
  7. An open dot like this is used to graph inequalities that are greater than, >, or less than, <. It means the independent variable is not included in the answer.
  8. A closed dot like thisis used to graph inequalities that are greater than or equal to, ≥, or less than or equal to, ≤. It means the independent variable is included in the answer.
What You've Got to Do
  1. Extract inequalities from story problems and model with manipulatives.
  2. Use manipulatives and mathematical writing to show how to solve inequalities.
  3. Write equations and inequalities to represent real-world variable situations.
  4. Solve equations and solve and graph inequalities that represent real-world variable situations.