$|2015x-2014|=|2015x+2014|$

2 câu trả lời

x4+2014x2-2014x-x+2014

=x(x3-1)+2014(x2-x-1)

=x(x-1)(x2-x-1)+2014(x2-x-1)

=(x2-x-1)(x2-x+2014)

-> Nên x bằng 2014

 

x4+2014x2-2014x-x+2014

=x(x3-1)+2014(x2-x-1)

=x(x-1)(x2-x-1)+2014(x2-x-1)

=(x2-x-1)(x2-x+2014)

-> Nên x bằng 2014