Prove that for positive values of a a\,a and bbb
16ab+9ba≥24 \frac{16a}{b} + \frac{9b}{a} \geq 24 b16a+a9b≥24Prove, by counterexample, that this is not true for all non-zero values of a a\,a and bbb.
257 exam-style questions on Edexcel A Level Maths Algebraic Methods, covering 7.1 Algebraic Fractions, 7.2 Dividing Polynomials, 7.3 The Factor Theorem, 7.4 Mathematical Proof, and 7.5 Methods of Proof. Each one has a worked solution and a mark scheme showing where the marks go.