（1）（m²-3m）²n+2n（m²-2m）+n=n[(m²-3m)²+2m²-4m+1]=n(m^4-6m³+9m²+2m²-4m+1)=n(m^4-6m³+11m²-4m+1)（2）x²+11x-80=(x-5)(x+16)（3）x²-10x-2...