Is xy > 0 ?
(1) x - y > -2
(2) x - 2y < -6
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
两个方法,一个是在坐标系画图,标记两个不等式的相交区域,可以看出在第一象限,所以成本。第二个是由题得,2x-2y>-4, 2y-x>6.相加得X>2,同理消去X,得y>4.,所以XY>0
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