Solving One-Step and Two-Step Equations

Learn to solve simple linear equations using inverse operations. Grade 9 Alberta mathematics.

Lesson 6.1 of Linear Equations & Inequalities in Grade 9 Math — Alberta curriculum lessons.

What you'll learn in this lesson

Inside the lesson — a free preview

Understanding Inverse

🔄 What is "Inverse"?. The word inverse means opposite.

In math, inverse operations are opposite actions that undo each other.

🎯 Our Goal When Solving Equations.

🔧 Why We Use Inverse Operations

The Strategy. To solve an equation, you "work backward."

You undo each operation in the opposite order that it was applied, so the variable becomes isolated.

⚖️ The Golden Rule of Equations

Keep It Balanced!. Whatever you do to one side,you must do to the other to keep the equation balanced — even when you're squaring or taking roots.

Understanding Two-Step Equations

🔢 What is a Two-Step Equation?. A two-step equation means the variable has two operations attached to it — for example, it's multiplied and then added.

To find the variable, we must undo both operations — one at a time — using their inverse operations.

⚠️ Important Rule. Always reverse the order of operations (work backward from BEDMAS).

Think: What was the last thing done to the variable? Undo that first!

📝 Our 4-Step Strategy

🎯 Strategy We'll Use Every Time.

Worked example: 📋 Step-by-Step Examples

Example 1 — Solving with Subtraction. Solve: x + 12 = 20

Example 2 — Solving with Division. Solve: 5x = 35

Example 3 — Solving with Square Root. Solve: x² = 64

Create a free Studyio account to take the full lesson with voice-over teaching, practice questions and instant feedback.