Question

5、5個(gè)非零實(shí)數(shù)相乘，結(jié)果為負(fù)．則負(fù)因數(shù)的個(gè)數(shù)為（　�。�

A、1個(gè)

B、3個(gè)

C、5個(gè)

D、1個(gè)或3個(gè)或5個(gè)

Answer 1

分析：幾個(gè)不為0的有理數(shù)相乘，積的符號(hào)取決于負(fù)因數(shù)的個(gè)數(shù)：當(dāng)負(fù)因數(shù)的個(gè)數(shù)是奇數(shù)時(shí)，則積的符號(hào)是負(fù)號(hào)；當(dāng)負(fù)因數(shù)的個(gè)數(shù)是偶數(shù)時(shí)，積的符號(hào)是正號(hào)．

解答：解：5個(gè)非零實(shí)數(shù)相乘，結(jié)果為負(fù)．則負(fù)因數(shù)的個(gè)數(shù)為奇數(shù)個(gè)，即1個(gè)或3個(gè)或5個(gè)．
故選D．

點(diǎn)評(píng)：此題考查了有理數(shù)的乘法法則．