已知a^3m=3,b^3n=2,（a^2m)^3+（b^n)^3-a^2m·b^n·a^4m·b^2n=（a^3m)^2+b^3n-a^(2m+4m)·b^(n+2n)=3^2+2-(3^2)·2=9+2-9*2=-7