If x and y are inegers greater than 1, is x the a multiple of y?
(1) 3y2+7y=x
(2) x2-x is a multiple of y
答案是(1) 我做出来不对 求大神解答
作者: Avengeryzc 时间: 2011-3-19 12:16
(1)x=y(3y+7) 所以x是y的倍数 (2)x(x-1)=ky x不一定是y的倍数 so a is sufficient .作者: kazemi 时间: 2011-3-19 12:17
(1)3y^2+7y=x y(3y+7)=x x/y=3y+7 y is inegers greater than 1, so 3y+7 is integer, then x/y is integer x is always a mutiple of y