\(3^{m+2}-2^{m+2}+3^m-2^m\left(m\in N\cdot\right)\)
\(=3^m.3^2-2^n.2^2+3^m-2^n=3^m.9-2^n.4+3^m-2^n\)
\(=3^m.9-2^n.4+3^m-2^n=3^m\left(9+1\right)-2^n\left(4+1\right)=3^m.10-2^n.5\)
\(=3^m.10-2^{n-1}.10=10\left(3^m-2^{n-1}\right)⋮10\left(m\inℕ^∗\right)\)