1：(x+y-z)^(3n)×(z-x-y)^(2n)×(x-z+y)^5
=(x+y-z)^(3n)×(x+y-z)^(2n)×(x+y-z)^5
=(x+y-z)^(5n+5)
2：a^m=2,a^n=3
①a^(m+n)=a^m×a^n=2×3=6
②a^(m+2n)=a^m×a^(2n)=a^m×(a^n)²=2×3²=18