原式=105×95+103×97-107×93-101×99
=(100+5)×(100-5)+(100+3)×(100-3)-(100+7)×(100-7)-(100+1)×(100-1)
=100×100-5×5+100×100-3×3-(100×100-7×7)-(100×100-1×1)
=-25-9+49+1
=16
原式=105×95+103×97-107×93-101×99
=(100+5)×(100-5)+(100+3)×(100-3)-(100+7)×(100-7)-(100+1)×(100-1)
=100×100-5×5+100×100-3×3-(100×100-7×7)-(100×100-1×1)
=-25-9+49+1
=16