#66
Finding the equation of a straight line from its gradient and a point
Algebra · Grade 4–6
Strand: Algebra
Substrand: Graphs and coordinates
Sparx code: U477
Sparx levels: 2, 3, 4, 5
Key steps (method)
- Simplify both sides first (remove brackets and collect like terms).
- Get all the x terms on one side and constants on the other.
- Use inverse operations step-by-step (undo +/− then ×/÷).
- If there are fractions, clear them by multiplying through by the LCM of denominators.
- Check by substituting your answer back into the original.
Common mistakes
- Doing different operations to the two sides of the equation.
- Sign errors when moving terms across the equals sign.
- Dropping brackets or mis-handling negatives.
- Not checking the final answer.
Quick notes
- If you get stuck, try a simpler version of the problem first or plug in easy numbers to test your method.
- For multi-step questions, label each step and keep intermediate results.
- For exam questions, always aim to make your work “mark-scheme readable”.
Self-assessment
- Can I define it? Write a one-sentence definition of Finding the equation of a straight line from its gradient and a point (or the key term in the question).
- Can I do it? Do 3 questions: one easy, one standard, one harder. Don’t look at notes until you’ve tried.
- Can I explain it? In 2–3 sentences, explain why the method works (or what would go wrong with a common mistake).
- Can I check it? State one quick check (estimate, units, sign, reasonableness).
Support videos
- YouTube (Edexcel GCSE Maths): https://www.youtube.com/results?search_query=edexcel%20gcse%20maths%20Finding%20the%20equation%20of%20a%20straight%20line%20from%20its%20gradient%20and%20a%20point
- YouTube (Corbettmaths): https://www.youtube.com/results?search_query=corbettmaths%20Finding%20the%20equation%20of%20a%20straight%20line%20from%20its%20gradient%20and%20a%20point
- YouTube (Maths Genie): https://www.youtube.com/results?search_query=maths%20genie%20Finding%20the%20equation%20of%20a%20straight%20line%20from%20its%20gradient%20and%20a%20point
Revision links
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Sparx topic code: U477 (paste into Sparx search)
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Maths Genie (topic questions): https://www.mathsgenie.co.uk/gcse.html
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Physics & Maths Tutor (Edexcel GCSE Maths): https://www.physicsandmathstutor.com/maths-revision/gcse-edexcel/