Two-Step Equations
Undo addition/subtraction, then multiplication/division.
Key idea
Undo addition/subtraction, then multiplication/division.
In depth
Undo operations in reverse order: first undo addition or subtraction, then undo multiplication or division. Think of unwrapping the variable layer by layer.
Worked example
3x + 5 = 20: subtract 5 → 3x = 15; divide by 3 → x = 5. Check: 3(5)+5 = 20.
Formula
Real-world uses
- Finding the number of hours worked from a pay slip
- Converting temperature between scales
Common mistake
Dividing first and forgetting to divide every term.
How to learn this
- Read the key idea and say it in your own words.
- Work through the worked example, then try a similar problem.
- Use the interactive lesson’s visual and mini-quiz to check the pattern.
Frequently asked questions
What is Two-Step Equations?
Undo addition/subtraction, then multiplication/division. It is a topic at the beginner level in Algebra.
What is the formula for Two-Step Equations?
The key formula is 2x + 3 = 11 ⇒ x = 4.
Where is Two-Step Equations used in real life?
Real-world examples: Finding the number of hours worked from a pay slip; Converting temperature between scales.
What should I learn before Two-Step Equations?
Make sure you are comfortable with One-Step Equations, the previous topic in Algebra.
What is a common mistake with Two-Step Equations?
Dividing first and forgetting to divide every term.
How can I practise Two-Step Equations?
Open the interactive lesson, play with the visual, then answer the three-question mini-quiz. Getting two right marks the topic complete.
What comes after Two-Step Equations?
Move on to Multi-Step Equations next.
Related beginner topics in Algebra
- Variables and Expressions – Letters stand for unknown or changing numbers in expressions.
- Evaluating Expressions – Substitute values for variables and simplify.
- Like Terms – Terms with the same variable part can be combined.
- Distributive Property – Multiplication spreads over addition.
- Simplifying Expressions – Combine like terms and apply distribution to write expressions compactly.
- Writing Expressions from Words – Translate phrases like “three more than twice a number” into algebra.