没有简便方法,直接去括号,合并同类项
1949×(1/51-1/2000)+51×(1/1949-1/2000)-2000×(1/1949-1/51)+3
=1949/51-1949/2000+51/1949-51/2000-2000/1949-2000/51+3
=(1949-2000)/51+(51-2000)/1949-(1949+51)/2000+3
=-1-1-1+3
=0
没有简便方法,直接去括号,合并同类项
1949×(1/51-1/2000)+51×(1/1949-1/2000)-2000×(1/1949-1/51)+3
=1949/51-1949/2000+51/1949-51/2000-2000/1949-2000/51+3
=(1949-2000)/51+(51-2000)/1949-(1949+51)/2000+3
=-1-1-1+3
=0