- 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)
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.
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.