oylimit
幼苗
共回答了22个问题采纳率:81.8% 举报
a > 0,b > 0时,
|a|/a + |b|/b + |ab|/ab = 1 + 1 + 1 = 3
a > 0,b < 0时,
|a|/a + |b|/b + |ab|/ab = 1 - 1 - 1 = -1
a < 0,b > 0时,
|a|/a + |b|/b + |ab|/ab = -1 + 1 - 1 = -1
a < 0,b < 0时,
|a|/a + |b|/b + |ab|/ab = -1 - 1 + 1 = -1
1年前
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