简便运算 1997+1998+1999+1198*97

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简便运算 1997+1998+1999+1198*97
简便运算 1997+1998+1999+1198*97

简便运算 1997+1998+1999+1198*97
1997+1998+1999+1998*97
=(1997+1)+1998+(1999-1)+1998*97
=1998*(3+97)
=199800

题目有误吧?

2000-3+2000-2+2000-1+(1200-2)*(100-3)
=6000-6+120000-3600-200+6
=6000+120000-3800
=126000-3800
=122200

1997+1998+1999+1198×97
= (1998-1)+1998+(1998+1)+1198×97
= 1998×3+1198×97
= (800+1198)×3+1198×97
= 800×3+1198×3+1198×97
= 2400+1198×(3+97)
= 2400+119800
= 122200

1997+1998+1999+1998×97=(1998-1)+1998+(1998+1)+1998×97=1998×(3+97)-1+1=199800