先化简,再求值:{[2a^2-18/a(a+3)-2(a+3)]/(-a-2)}*{[a^2(a-3)+4(3-a)/a

{[2a^2-18/a(a+3)-2(a+3)]/(-a-2)}*{[a^2(a-3)+4(3-a)/a^2-6a+9]},其中a=2012-7根号3
={[2(a-3)(a+3)/a(a+3)-2(a+3)]/(-a-2)}{[a²（a-3)-4(a-3)/(a-3)²]}
={{2(a-3)/(a-2)(a+3)]/(-a-2)}{[(a-3)(a²-4)/(a-3)²]}
=[2(a-3)(a-3)(a-2)(a+2)/[-(a+2)(a-3)²]
=-2(a-2)
=-2(2012-7√3-2)
=-4020+14√3