原式=[(x-2)(x+2)-5]/(x+2)*(2x+4)/(x-3)
=(x²-9)/(x+2)*(2x+4)/(x-3)
=(x+3)(x-3)/(x+2)*2(x+2)/(x-3)
=2x-6代值是多少哦，对不起原式=2x-6=2√2-6-6=2√2-12