问题 解答题
脱式计算.
909-(317+538)=63÷7×21=302×(504-498)=
答案

(1)909-(317+538),

=909-855,

=54;

(2)63÷7×21,

=9×21,

=189;

(3)302×(504-498),

=302×6,

=1812.

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