Equations & Formulae
Solve simple linear equations using inverse operations and substitute values into simple formulae.
Overview
An equation says that two expressions are equal, and solving it means finding the value of the unknown that makes it true. In Year 7 students solve simple one- and two-step linear equations using inverse operations, and substitute values into simple formulae. The idea of keeping an equation balanced is one of the most powerful ideas in maths.
What You Will Learn
- Understand that an equation must stay balanced on both sides
- Solve one-step equations using inverse operations
- Solve two-step equations such as 3x + 4 = 19
- Substitute values into a simple formula to find a result
- Check a solution by substituting it back into the equation
Key Vocabulary
Common Mistakes to Avoid
- Doing the inverse operations in the wrong order in a two-step equation
- Changing only one side of the equation so it is no longer balanced
- Using the same operation instead of the inverse (e.g. adding when you should subtract)
- Forgetting to check the answer by substituting it back in
What Comes Next
Year 8 moves on to equations with brackets and with the unknown on both sides, and Year 9 rearranges formulae. Solving equations is central to every IGCSE Algebra paper.
Frequently Asked Questions
What does 'inverse operation' mean?
It is the operation that undoes another. Addition and subtraction are inverses, and multiplication and division are inverses. To solve an equation you undo each operation in reverse order.
How do I know my solution is correct?
Substitute your answer back into the original equation. If both sides are equal, your solution is correct.
Study This Topic
Topic Details
- Stage
- Year 7
- Strand
- Algebra
- Framework ref
- 7Ae
- Difficulty
- Medium
Build strong foundations in Equations & Formulae
A free trial class with Teacher Rig helps your Year 7 child master Equations & Formulae now — so IGCSE Maths feels familiar, not frightening, later.
Heading toward IGCSE? See how Equations & Formulae develops in IGCSE Algebra and Graphs (Cambridge 0580) →