9999*7778+3333*6666
=9999×7778+3333×3×2222
=9999×7778+9999×2222
=9999×(7778+2222)
=9999×10000
=99990000
(425*5775+4225*425)/125/8
=425(5775+4225)/1000
=425*1000/1000
=425