计算：(a^2-8a+16)/(9-a^2 ) ÷(16-a^2)/(9+6a+a^2 )_数学解答

计算：(a^2-8a+16)/(9-a^2 ) ÷(16-a^2)/(9+6a+a^2 )

人气：419 ℃　时间：2020-03-26 06:26:02

解答

原式=(a-4)²/(a+3)(a-3)÷[-(a+4)(a-4)/(a+3)²]=-(a-4)²/(a+3)(a-3)×(a+3)²/(a+4)(a-4)=-(a-4)/(a-3)×(a+3)/(a+4)=(-a²+a+12)/(a²+4a-12)