84乘以101减84
= 84×(101-1)
=84×100
=8400
11分之4+7分之3+11分之7+7分之2
=(4/11 +7/11)+(3/7 +2/7)
= 1+ 5/7
= 12/7
7分之6乘以(6分之5-2分之1)+2分之1
= 6/7 × 1/3 +1/2
= 2/7 +1/2
= 11/14
2009乘以2008分之2007
=(2008+1)× 2007/2008
= 2008 × 2007/2008 + 2007/2008
= 2007 + 2007/2008
= 2007又2008分之2007
秋风燕燕为您答题 O(∩_∩)O
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