原式=a的6m次方+b的6m次方-a的6m²次方×b的3m次方×b的m次方
=a的6m次方+b的6m次方-a的6m²次方×b的3m²次方
=[a^(3m)]^2+[a^(2m)]^3-[a^(3m)]^2*[b^(2m)]^2
=2²+3³-2²×3²
=4+27-36
=-5
如有不懂之处,欢迎追问.