Question

487-187-139-61=?300-123-77-75=?3200/4/25=?72*125=?运用减法交换 乘法分

Answer 1

487-187-139-61

=487-187-(139+61)

=300-200

=100

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300-123-77-75

=300-(123+77)-75

=300-200-75

=25

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3200/4/25

=3200/(4*25)

=3200/100

=32

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72*125

=72*100+72*20+72*5

=7200+1440+360

=7200+1800

=9000