6.86乘【负5】加6.86乘【负12】加6.86乘【正17】,等于几等于几.等于几.
问题描述:
6.86乘【负5】加6.86乘【负12】加6.86乘【正17】,等于几等于几.等于几.
答
=-6.86×5-6.86×12+6.86×17
=6.86×(-5-12+17)
=6.86×0
=0