a²-4/a²+6a+9除a-2/2a+6,其中a=-5

问题描述:

a²-4/a²+6a+9除a-2/2a+6,其中a=-5

(a²-4/a²+6a+9)/(a-2/2a+6)
=(a+2)(a-2)/(a+3)^2*2(a+3)/(a-2)
=2(a+2)/(a+3)
=2*(-5+2)/(-5+3)
=3