脱式计算，能简算的要简算．999×999+1999（115+217）×15×172012×2010201158×98+38×100．

Question

脱式计算，能简算的要简算．
999×999+1999                     
（(1)/(15)+(2)/(17)）×15×17
2012×(2010)/(2011)
(5)/(8)×98+(3)/(8)×100．

Answer 1

（1）999×999+1999
=999×999+999+1000
=（999+1）×999+1000
=1000×999+1000
=（999+1）×1000
=1000×1000
=1000000；

（2）（(1)/(15)+(2)/(17)）×15×17
=(1)/(15)×15×17+(2)/(17)×15×17
=17+30
=47；

（3）2012×(2010)/(2011)
=（2011+1）×(2010)/(2011)
=2011×(2010)/(2011)+(2010)/(2011)
=2010+(2010)/(2011)
=2010(2010)/(2011)


（4）(5)/(8)×98+(3)/(8)×100
=(5)/(8)×98+(3)/(8)×（98+2）
=(5)/(8)×98+(3)/(8)×98+(3)/(8)×2
=（(5)/(8)+(3)/(8)）×98+(3)/(4)
=1×98+(3)/(4)
=98(3)/(4)