Question

x(x+1)(x+2)+9=y(y^2+2) tìm x;y nguyên

Answer 1

=>x(x^2+3x+2)+9-y^3-2y=0

=>x^3+3x^2+2x+9-y^3-2y=0

=>(x-y)(x^2+xy+y^2)+2(x-y)+3(x^2+3)=0

=>(x-y)(x^2+xy+y^2+2)+3(x^2+3)=0

=>PTVN

Answer 2

=>x(x^2+3x+2)+9-y^3-2y=0

=>x^3+3x^2+2x+9-y^3-2y=0

=>(x-y)(x^2+xy+y^2)+2(x-y)+3(x^2+3)=0

=>(x-y)(x^2+xy+y^2+2)+3(x^2+3)=0

=>PTVN