Question

7、幾個不等于0的有理數(shù)相乘，它們的積的符號如何確定

當(dāng)負數(shù)個數(shù)為偶數(shù)時，積為正數(shù)，當(dāng)負數(shù)個數(shù)為奇數(shù)時，積為負數(shù)

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Answer 1

分析：幾個不等于0的有理數(shù)相乘，它們的積的符號有負數(shù)的個數(shù)確定．

解答：解：根據(jù)幾個不等于零的數(shù)相乘，積的符號由負因數(shù)的個數(shù)決定：當(dāng)負因數(shù)有奇數(shù)個數(shù)，積為負；當(dāng)負因數(shù)的個數(shù)為偶數(shù)個時，積為正．
故答案為：當(dāng)負數(shù)個數(shù)為偶數(shù)時，積為正數(shù)，當(dāng)負數(shù)個數(shù)為奇數(shù)時，積為負數(shù)

點評：本題考查了有理數(shù)的乘法，幾個不等于零的數(shù)相乘，積的符號由負因數(shù)的個數(shù)決定：當(dāng)負因數(shù)有奇數(shù)個數(shù)，積為負；當(dāng)負因數(shù)的個數(shù)為偶數(shù)個時，積為正．