(-1.3)+【-4,(-2,-7)】=(-1.3)+【-4,-7】=-1.3-4=-5.3
-5.3
解: (-1.3)+【-4,(-2,-7)】=-1.3 + 【-4,-7】=-1.3 + (-4)=-5.3
(-1.3)+[-4,(-2,-7)]=-1.3-4=-5.3