Two-Step Equations
Most GED equations require two inverse operations — undo addition or subtraction first, then undo multiplication or division.
This is a free explanation of Two-Step Equations — a preview, not the full interactive lesson. The lesson, practice, quizzes, and AI Tutor are inside the app.
Think of an equation as a balance scale: whatever you do to one side, you must do to the other to keep it balanced. Your goal is to isolate the variable — get it alone on one side — by applying inverse (opposite) operations to undo whatever is attached to it.
Work in reverse order of PEMDAS. For 2x + 7 = 15, the x is multiplied by 2 and then 7 is added, so you undo the addition first (subtract 7 from both sides), then undo the multiplication (divide both sides by 2).
After solving, always check your answer by substituting it back into the original equation. If both sides equal the same number, you solved it correctly — a simple arithmetic slip is caught this way.
Worked example
Solve: 2x + 7 = 15
- Undo the addition first: subtract 7 from both sides. 2x + 7 − 7 = 15 − 7, so 2x = 8.
- Undo the multiplication: divide both sides by 2. 2x ÷ 2 = 8 ÷ 2.
- Check: substitute x = 4 into the original: 2(4) + 7 = 8 + 7 = 15.
x = 4
On the test: Two-step equations are the most common equation type on the GED & HiSET.
Inside the app, Two-Step Equations comes with:
Read the explanation here for free — then practice it for real, with everything you need in one place.
- Practice sets — Open-book practice questions at your level, easiest-first — as many as you want, never scored.
- Quizzes — Scored quizzes on the whole lesson, so you know when you’re ready to move on.
- Skills Check — A concept-by-concept map of what you’ve mastered and what to focus on next.
- Worked examples — Tap the Brain Button on any example for alternative step-by-step explanations.
- Glossary — Plain-English definitions of every key term in the lesson.
- Formula sheet — The GED® & HiSET® formula sheets, on screen while you practice.
- Practice calculator — An on-screen calculator to build your calculator skills before test day.
- Math-fact flashcards — Quick drills for addition, multiplication, perfect squares, and square roots.
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