Student Goal

I can solve multi-step equations and inequalities and explain what the solution means.

Why It Matters

Equations and inequalities are used throughout Math 1 to solve problems, compare quantities, and describe constraints.

Warm-Up

Warm-Up 1

Solve x - 6 = 14.

Warm-Up 2

What happens to the symbol when you divide -2x < 10 by -2?

Short Lesson

Standard Focus

NC.M1.A-REI.1 and NC.M1.A-REI.3: Solving equations and inequalities

Student-Friendly Standard Goal

I can justify steps for solving equations and inequalities in one variable.

  • Use inverse operations to isolate the variable.
  • Whatever you do to one side, do to the other side.
  • Combine like terms before solving when it makes the equation simpler.
  • When multiplying or dividing an inequality by a negative number, reverse the inequality symbol.

Guided Examples

Guided Example 1

Solve a Multi-Step Equation

Solve 3(x - 2) = 18.

Step 1

3(x - 2) = 18

Which efficient first step works?

Guided Example 2

Solve an Inequality

Solve -4x + 3 \ge 15.

Step 1

-4x + 3 \ge 15

What do you get after subtracting 3?

Practice

Problem 1

Solve 5x + 4 = 29.

Problem 2

Solve 2(x + 3) = 16.

Problem 3

Solve x/3 - 2 > 4.

Problem 4

Error analysis: A student solves -x > 7 and writes x > -7. What is wrong?

Problem 5

True or false: x = 4 solves 2x + 1 = 9.

Reflection

How are you feeling about today's skill?

Optional reflection: What is one step, word, or representation from today that you want to remember when Math 1 starts?