问题 解答题

脱式计算.

85+79×85-79

78+(6500-140×41)

65+225÷(135-130)

答案

(1)85+79×85-79

=85×(1+79)-79

=85×80-79

=6800-79

=6721;

(2)78+(6500-140×41)

=78+(6500-5740)

=78+760

=838;

(3)65+225÷(135-130)

=65+225÷5

=65+45

=110.

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