A cubic storage unit is designed such that its side length, x x\,x meters, is an integer. An engineer claims that if the volume of the unit, V=x3V = x^3V=x3, is a multiple of 3, then the side length x x\,x must be a multiple of 3. Use proof by contradiction to prove that the engineer's claim is correct.
368 exam-style questions on Edexcel A Level Maths Algebraic Methods, covering 1.1 Proof by Contradiction, 1.2 Algebraic Fractions, 1.3 Partial Fractions, 1.4 Repeated Factors, and 1.5 Algebraic Division. Each one has a worked solution and a mark scheme showing where the marks go.