(125×99+125)×16
=125×(99+1)×8×2
=(125×8)×100×2
=1000×100×2
=200000
5×999+5+99×7+7+3×9+3+9
=5×(999+1)+7×(99+1)+3×(9+1)+9
=5×1000+7×100+3×10+9
=5000+700+30+9
=5739