Respuesta :

[tex]\begin{gathered} (3x^2^{}-5x+3)+(-3x^2+5x-3) \\ \end{gathered}[/tex]

so we group

[tex]\begin{gathered} (3x^2-3x^2)+(-5x+5x)+(3-3) \\ 0+0+0 \\ =0 \end{gathered}[/tex]