MathDB
Operations on a quadratic

Source: Philippines MO 2016/1

January 21, 2017
algebrainvariantDiscriminantquadratics

Problem Statement

The operations below can be applied on any expression of the form ax2+bx+cax^2+bx+c.
(I)(\text{I}) If c0c \neq 0, replace aa by 4a3c4a-\frac{3}{c} and cc by c4\frac{c}{4}.
(II)(\text{II}) If a0a \neq 0, replace aa by a2-\frac{a}{2} and cc by 2c+3a-2c+\frac{3}{a}.
(IIIt)(\text{III}_t) Replace xx by xtx-t, where tt is an integer. (Different values of tt can be used.)
Is it possible to transform x2x6x^2-x-6 into each of the following by applying some sequence of the above operations?
(a)(\text{a}) 5x2+5x15x^2+5x-1
(b)(\text{b}) x2+6x+2x^2+6x+2