因式分解:a3-a = .
a(a-1)(a + 1)
分析:先提取公因式a,再对余下的多项式利用平方差公式继续分解.
解答:解:a3-a,
=a(a2-1),
=a(a+1)(a-1).
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A.trouble
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试述肾素-血管紧张素-醛固酮系统在调节血压中的作用。