Assume that xxx and yyy are integers such that
x2−8y−6=0x^2 - 8y - 6 = 0x2−8y−6=0
Prove that xxx is even.
Hence, prove that 4y+34y + 34y+3 is even and explain why this leads to a contradiction.
Explain what can be deduced about the integer solutions to the equation x2−8y−6=0x^2 - 8y - 6 = 0x2−8y−6=0.
Practise Edexcel A Level Maths 1.1 Proof by Contradiction with exam-style questions for A Level Maths. 100 questions, matched to the Edexcel A Level Maths (9MA0) 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.