设随机变量X的概率密度为px(x ),令 Y=-6-|||-+2, 则Y的概率密度pr (y)为 ()()-|||-(A) 6px(-6y)-|||-(B) (-dfrac (y-2)(6))-|||-(C) -dfrac (1)(6)px(-dfrac (y-2)(6))-|||-(D) dfrac (1)(6)px(-dfrac (y-2)(6))