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This is a quadratic equation, and is likely that x can satisfy either of two values. We know these must multiply to form 20 and summate to -9, and thus they are (x-4) and (x-5). Hence, x is either 4 or 5....

16 = (x-3)(x+3) --> 16 = x^2+3x-3x-9 --> 16 = x^2-9 --> x^2=25 --> x = +5 or -5

First of all expand the brackets and simplify the expression given:(4n+1)(4n+1)-(2n-1)= 8n²+8n+1-2n+1= 8n²+6n+2= 2(4n²+3n+1). Since the expression can be factorised with 2...

While I doubt students will ask this exact question, think it provides the basis for what are usually the most difficult questions in GCSE papers, and students would usually be unsure where to start. My i...