(1)450-225÷5+135,
=450-45+135,
=405+135,
=540;
(2)25×71×4,
=25×4×71,
=100×71,
=7100;
(3)99×425,
=(100-1)×425,
=100×425-1×425,
=42500-425,
=42075;
(4)101×79-79,
=(101-1)×79,
=100×79,
=7900;
(5)304+306÷17-298,
=304+18-298,
=322-298,
=24.