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66×99=514-389-111=87×201=

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答案和解析
(1)66×99
=66×(100-1)
=66×100-66×1
=6600-66
=6504;

(2)514-389-111
=514-(389+111)
=514-500
=14;

(3)87×201
=87×(200+1)
=17400+87
=17487.