解析：先进行“分离变量”,再用均值不等式y=(2x^2-12x+18+12x-18)/(x-3) =[2(x-3)^2+12(x-3)+18]/(x-3) =2(x-3)+18/(x-3)+12 【∵x>3,∴x-3>0】 >=12+2*根号[2（x-3)*18/(x-3)] =12+2*6 =24故：Ymin=24...