参考2-m=1,n-1=1∴m=1,n=2∴m²-(-3mm+3n²)+2n² 或m²-(-3mn+3n²)+2n²＝m²＋3m²－3n²+2n²或m²＋3mn－3n²+2n²＝4m²－n² ...