a=5a = 5a=5 b=−7b = -7b=−7 c=1c = 1c=1
Work out the value of b2−4acb^2 - 4acb2−4ac
Practise Edexcel GCSE Maths Substitution with exam-style questions for Foundation and Higher tier. 100 questions, matched to the Edexcel GCSE Maths (1MA1) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.