- 数学题12345*12321
- 12345*12321-12344*12321+12345*42000-12344*42001
- 解：12345*12321-12344*12321+12345*42000-12344*42001
=12345*12321+12345*42000-12344*12321-12344*42001
=12345*（12321+42000）-12344*（12321+42001）
=12345*54321-12344*54322
=（12344+1）*（54322-1）-12344*54322
=12344*54322+54322-12344-1-12344*54322
=54322-12344-1
=41977