Answer :
The difference between the two expressions is;
[tex]3n^3-n^2-1[/tex]Here, we want to find the difference between the given expressions
To do this, we open up the right expression; afterwards, we bring similar terms together
Mathematically, we have this as follows;
[tex]\begin{gathered} (3n^3-2n+7)-(n^2-2n+8) \\ =3n^3-2n+7-n^2+2n-8 \\ =3n^3-2n+2n-n^2+7-8 \\ =3n^3-n^2-1 \end{gathered}[/tex]