This exam tips covers Exam Tips for Linear Graphs Problems within Linear Graphs Problems for GCSE Mathematics. Revise Linear Graphs Problems in Graphs for GCSE Mathematics with 16 exam-style questions and 11 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 7 of 10 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
💡 Exam Tips for Linear Graphs Problems
- Always check your equation: substitute both original points back in to verify
- For graphical simultaneous equations: draw accurate lines and read coordinates precisely — errors in plotting will give wrong answers
- In context questions: always write units with your gradient (£/hour, km/h, etc.)
- Fixed charge vs variable cost: y-intercept = fixed charge; gradient = cost per unit
- Rearrange first: if the equation is not in y = mx + c form, rearrange before identifying m and c
- Negative gradient in context: means the quantity is decreasing (e.g. fuel tank emptying, candle burning down, value depreciating)
Practice questions for Linear Graphs Problems
A taxi company charges a fixed fee plus an amount per mile. On a cost graph (£ against miles), what does the y-intercept represent?
A plumber charges according to the formula C = 40t + 30, where C is the total cost in pounds and t is the time in hours. Explain what the values 40 and 30 represent in this context.